repair wall plate?

[Cubist]

I don't dispute the need for, and urgency in, installing props. My first concern at present is with making sure that the frame is not further damaged by the use of straps and needle jacks by siting them under/around the beams. Currently the condition of the mortice and tenon joints, and the pegs that should be locking these together may be largely unknown. The risk is that any 'lift' or 'compression' forces operating on the beams alone may induce failure of the joints and/or the beams. Great care is needed in the siting of straps and needle jacks.

With the information provided thus far it seems clear to me that the root cause of the roof spread is a failure of the truss sited atop the post that has been pushed from vertical and its partner post in that bent. As a consequence the post and everything above it is effectively 'hinging' on the main lateral beams connecting the bents that are in turn carrying the joists and floors above and ceilings below. Presently, as the bottom of the sloping post and the sill plate to which it is attached are floating I'm wondering what if any measures in the current plan will help to correct this?

Regarding on-site fabrication and in-situ welding of the proposed steels. The fire risk associated with this is clear but I am wondering whether the design and implementation methods for these steels will be a help or a hindrance to the long terem solution to correct issues with the post and truss?

 

[noj]

Realistically you can't apply for LBC until you've decided what you want to do and with what materials.

 

[GerryC]

we are committed to like for like and the daub will be reconstituted ... but the insertion of metal frame + we will propose not to use yorkshire window in this position where it is am open well for rain

 

[Cubist]

Gerry,

Sorry about this but.....

Bad News - In my opinion the current plan of work is deeply flawed and will prove to be little better than a sticking plaster over the wound. In fact besides being a waste of considerable amounts of time, resources and money I believe these works could introduce a new risk that could, quite literally, bring the house down!

Good News -there is a solution, that would be far cheaper, less invasive, more acceptable to the planning authorities and far better for the house.

Please stop and re-evaluate.

 

[a twig]

Probably worth mentioning that the thoughts and comments provided by members of this forum are just that, and should not be construed as professional advice.

None of us post on here in a professional capacity, views and opinions are provided for the homeowner to take on and evaluate at their own behest, and homeowners are recommended to take advice from professionals backed by large liability insurance policies should they have any concerns.

 

[GerryC]

Presently, as the bottom of the sloping post and the sill plate to which it is attached are floating I'm wondering what if any measures in the current plan will help to correct this?

Hi Steve, i/we assumed that once all walls stripped down to the frame we will repair/replace/correct the position of all the posts / braces etc. as found necessary - the support frame proposed by the engineer then stops roof spread pushing the tops of the posts/beams outward. Seems plausible to me and elegant in that the frames fit through the floorboards alongside the joists. I did wonder and did ask if the beams would be strong enough not to snap with the strapping and also if the beams integrity could be compromised by placing 4 bolts through them and therefore break later ... the Engineer was confident neither was of concern. (On the strapping i'd suggested use of a support beam put through the straps on the outside of the plate to spread the bearing of the loads along it rather than have concentrated force where the straps are (this was before you kindly let me know you strap to posts/joints not beam. The Engineer said no need so long at tension very slowly he envisiaged no problems).

 

[GerryC]

Gerry,

Sorry about this but.....

Bad News - In my opinion the current plan of work is deeply flawed and will prove to be little better than a sticking plaster over the wound. In fact besides being a waste of considerable amounts of time, resources and money I believe these works could introduce a new risk that could, quite literally, bring the house down!

Good News -there is a solution, that would be far cheaper, less invasive, more acceptable to the planning authorities and far better for the house.

Please stop and re-evaluate.

Hi Steve, I'm filled with hopeful anticipation, do let us have it, please ...

 

[malcolm]

I was feeling Cubist might have been overdramatic. I had a look at the thread and I think he's right.

Assuming you are plastered/rendered inside and out then you've got no idea what condition the structure is in and neither does the structural engineer. Her plans are predictable - they always like to ignore any existing structure and just add a new structure back to the ground. In this case a new structure back to the sole plate with the caveat replace sole plate as necessary.

The existing structure should be able to work without new bits. It's clearly damaged. I didn't read too closely but I'm guessing concrete render and waterproof paint on the outside which tends to ensure the timber frame gets really wet and becomes food for beetles. I would strip that off to see what has failed. The exterior render must be lime and the coatings breathable like limewash so the water can get out so that job needs doing anyway. Whatever you decide the cement and waterproof paint has to go else there will be nothing left of the frame.

If it were me I would strip the cement render from the house to assess the structure. You don't need any permission as it's a repair if you plan to render again with lime. Get in touch with a timber frame specialist. You'll need a timber frame specialist anyway as your sole plate isn't where the structural engineer would like it. I think the structural engineer is wasted money. Likely planning permission is wasted money too as you don't need it for repairs. It does look like a fairly serious repair job by a timber frame company is needed. Or DIY it if you have some experience with wood.

 

[GerryC]

I was feeling Cubist might have been overdramatic. I had a look at the thread and I think he's right.

Assuming you are plastered/rendered inside and out then you've got no idea what condition the structure is in and neither does the structural engineer. Her plans are predictable - they always like to ignore any existing structure and just add a new structure back to the ground. In this case a new structure back to the sole plate with the caveat replace sole plate as necessary.

The existing structure should be able to work without new bits. It's clearly damaged. I didn't read too closely but I'm guessing concrete render and waterproof paint on the outside which tends to ensure the timber frame gets really wet and becomes food for beetles. I would strip that off to see what has failed. The exterior render must be lime and the coatings breathable like limewash so the water can get out so that job needs doing anyway. Whatever you decide the cement and waterproof paint has to go else there will be nothing left of the frame.

If it were me I would strip the cement render from the house to assess the structure. You don't need any permission as it's a repair if you plan to render again with lime. Get in touch with a timber frame specialist. You'll need a timber frame specialist anyway as your sole plate isn't where the structural engineer would like it. I think the structural engineer is wasted money. Likely planning permission is wasted money too as you don't need it for repairs. It does look like a fairly serious repair job by a timber frame company is needed. Or DIY it if you have some experience with wood.

Hi Malcolm and thanks, ... certainly your main point i quite agree and believe we are doing ... yes get rid of cement (and cement render) and waterproof paint will go and before we can be sure of any actions (although there is a plan) we need to strip down to frame and see whats what with the frame (thats the main reason i started this thread with 3 specific questions re propping). As regards what the plan should be to prevent future roof spread i'd be glad to hear alternatives to the one i have been given. I did query with the Engineer both knee braces and large brick piers but he had good reasons for these note being good (the joists on the first floor are well under spec and fitting kneee braces to already leaning wall ... piers would have to be huge...). So i'm looking forward to hear what Steve's (Cubist) solution is ....

BTW would you recommend removing the cement render and plater without propping the frame first (considering border line 11 degree lean)?

 

[malcolm]

I would remove just enough to get some props in first before removing the render. You don't know what's in there and best to play safe.

 

[Cubist]

Apologies, I've been on the road for the last few hours.

I'm thinking that Twig may be a lawyer, but he is quite right, and as I said before, you should not rely on any advice here unless you verify it with a suitably qualified professional, With that aside let me first explain my worry concerning the plans you shared earlier with us and why these may pose a significant threat to the house,

By introducing the proposed steel reinforcements to both the posts and the beams you will indeed be stiffening the frame to resist further truss/rafter spread. However, if no work is done to repair and strengthen the key points of failure at the root of the problem, that stiffening of the frame could lead to a situation in which, should there be a significant additional load on the roof, the truss member mounted on the already leaning post may fracture its joint and/or skip out of its retaining socket. Given the potential size and weight of that truss member, its partner truss member and any ridge beam that may be connected at the apex collectively they represent a very real risk that much of the roof could collapse into the house.

My solution is predicated on the assumption that my understanding of the cause of all the major problems with the house are rooted in a failure, partial or total, of the mortice and tenon joint used to connect the principal members of the truss at its apex. Snow and other loads have translated through these members to produce the rafter spread observed and this force has operated at the weakest point in the frame to push the top of the post post away from the house and, through hinging on the beams connecting the bents at the first floor level, resulted in the large 'kick-out' of the base of the post and taking with it the attached sill beam. It should be very easy to verify this by checking the condition of the joint at the apex - be aware though that the separation of the truss timbers at the apex may only need to be as little as a couple of inches to produce a 'kick-out' of over a foot at the base of the post. The leaning post is the key to how I think all the major problems can be rectified. Ostensibly, and in short, I am proposing that the post is used as a lever to lift the foot of the failed truss member back to its original position to allow the installation of steel truss plates, on both sides of the truss timbers, at the apex of the truss. These truss plates must be of a size and design such that they provide all the required resistance to future snow and other loads. Other brackets may also be needed at the points where the truss members meet the post and other locations in the frame where the mortice and tenon joints may have been damaged or seriously weakened. Setting aside the cost of the steels needed, I believe that the job of bringing the post back to vertical and re-establishing the mechanical connections between the frame elements could be done reasonably easily with a winch, a couple of suitable straps, a few jacks and acrow props. Clearly, great care and careful co-ordination will be needed to pull the post back to vertical while ensuring that the truss members return to their original position and that actions are taken in a timely fashion to remedy any problems or obstructions that may arise during the lifting operation. Its also worth noting that among the preparations it will be essential to remove any render that may inhibit or block the required movement of the timbers and infill panels,


All the above should fall within the 'essential repair' category and, since you would not be making any material alterations to the property the likelihood of significant objections from the planning authorities would be much reduced if not rendered irrelevant - nevertheless, its always wise to stay in the CO's good books, talk to him/her, you may find that he/she could be very helpful and point you to local professionals whose opinions are respected.

 

[Cubist]

The Engineer said no need so long at tension very slowly he envisiaged no problems)

This one sentence tells me all I need to know about your engineer. It's not the 'rate/speed' at which the pressure is applied to the beam! it is what 'final load' will cause the beam, or its joints to the post, to fail!

This advice from him is nothing short of utter and dangerous nonsense.

 

[GerryC]

Apologies, I've been on the road for the last few hours.

I'm thinking that Twig may be a lawyer, but he is quite right, and as I said before, you should not rely on any advice here unless you verify it with a suitably qualified professional, With that aside let me first explain my worry concerning the plans you shared earlier with us and why these may pose a significant threat to the house,

By introducing the proposed steel reinforcements to both the posts and the beams you will indeed be stiffening the frame to resist further truss/rafter spread. However, if no work is done to repair and strengthen the key points of failure at the root of the problem, that stiffening of the frame could lead to a situation in which, should there be a significant additional load on the roof, the truss member mounted on the already leaning post may fracture its joint and/or skip out of its retaining socket. Given the potential size and weight of that truss member, its partner truss member and any ridge beam that may be connected at the apex collectively they represent a very real risk that much of the roof could collapse into the house.

My solution is predicated on the assumption that my understanding of the cause of all the major problems with the house are rooted in a failure, partial or total, of the mortice and tenon joint used to connect the principal members of the truss at its apex. Snow and other loads have translated through these members to produce the rafter spread observed and this force has operated at the weakest point in the frame to push the top of the post post away from the house and, through hinging on the beams connecting the bents at the first floor level, resulted in the large 'kick-out' of the base of the post and taking with it the attached sill beam. It should be very easy to verify this by checking the condition of the joint at the apex - be aware though that the separation of the truss timbers at the apex may only need to be as little as a couple of inches to produce a 'kick-out' of over a foot at the base of the post. The leaning post is the key to how I think all the major problems can be rectified. Ostensibly, and in short, I am proposing that the post is used as a lever to lift the foot of the failed truss member back to its original position to allow the installation of steel truss plates, on both sides of the truss timbers, at the apex of the truss. These truss plates must be of a size and design such that they provide all the required resistance to future snow and other loads. Other brackets may also be needed at the points where the truss members meet the post and other locations in the frame where the mortice and tenon joints may have been damaged or seriously weakened. Setting aside the cost of the steels needed, I believe that the job of bringing the post back to vertical and re-establishing the mechanical connections between the frame elements could be done reasonably easily with a winch, a couple of suitable straps, a few jacks and acrow props. Clearly, great care and careful co-ordination will be needed to pull the post back to vertical while ensuring that the truss members return to their original position and that actions are taken in a timely fashion to remedy any problems or obstructions that may arise during the lifting operation. Its also worth noting that among the preparations it will be essential to remove any render that may inhibit or block the required movement of the timbers and infill panels,


All the above should fall within the 'essential repair' category and, since you would not be making any material alterations to the property the likelihood of significant objections from the planning authorities would be much reduced if not rendered irrelevant - nevertheless, its always wise to stay in the CO's good books, talk to him/her, you may find that he/she could be very helpful and point you to local professionals whose opinions are respected.

Ah, it sounds as though you’ve seen this before Steve? ... The roof had top-coat of thatch done about 4 years ago (for which I propped the front wall with acrows / strongboys) and they didn’t encounter any failures. But what you say makes total sense to me – the extent to which the wall plate is moved out (about 11 degrees) must have an affect/relationship on the rafter(s) and as the pic I included before of the inside lintel on the dormer shows,
The suspect rafter has dropped a little.

The roof above the collar tie is not easily accessible … its has a very old ceiling which may be wattle-and-daub .. currently it can only be seen into from the neighbours rood cavity with a spotlight (it was the engineers first port of call) but that may not give a good enough view to confirm exact status of the joint in question and i don't think we even know the type of joints used. I will check again with engineer and neighbour about getting into it but another issue would be the safety of putting ones full body eight on a bit of structure not designed for that. And if I make a hatchway in our ceiling so it becomes accessible from our side, I would have to mount a ladder and would be a little concerned that the 1st floor will be OK. Joists are under spec but I can
prop the floor up temporarily. I will come back and let you know if I can get in to see what’s what there.

You said this solution less work, cost and disturbance. New to the idea, I’m struggling to see how it could be effected without removing a lot of thatch? Apart from getting enough visibility to be accurate, the rafter will be hard to move under the weight of the thatch, no?

And are the steel truss elements you are talking about essentially joint brackets or larger connecting members?

And, again, should I prop before I do further investigation … if so I would very much appreciate a little mre of your advise / pointer to some explanation re rachet strapping and how to place the straps around post-beam joint.

Thanks so much for your interest and help on this, makes it a good world. ATB

 

[Cubist]

Hi Gerry,

Indeed I have seen this kind of failure before and in both large and small timber frame structures. Before we acquired this old place I conducted, with occasional help from timber frame specialists, personal assessments of timber frame homes we were interested in perhaps buying. I was also considering building such a house myself and have invested a fair amount of effort in learning about the traditional methods of their construction.

Oddly, I have an example of this kind of truss failure here at Fircroft. Gratefully, this is not in the main house but in an old wood/garden shed in the grounds.

The load spread for your thatcher, even if he were a giant of a man, would typically not be sufficient to produce any significant issues. The bulk of his weight would have been directed down through the rails of his ladders directly to the ground with only a small proportion of his weight then being distributed over a much larger area of the roof. It's also true that the 'common rafters' installed between the ridge beam and the top plate and between the trusses will also have helped to distribute his weight. These common rafters may also have contributed to reducing the overall scale of the damage to your house when the truss or truss joint failed.

Thank you for including this latest diagram giving a cross section view of the house. I had been considering producing a crude diagram to illustrate what I believe the root cause of your problems to be and help me explain the remedial steps. Your cross section view roughly translates into a digram of a 'bent', i.e. a single timber frame of posts and beams which, when joined to other bents via horizontal beams forms the skeletal structure of the building. Typically, the bents would be constructed flat at ground level and all the joints between what will become the posts, beams, trusses and any braces of each bent would have been joined with mortice and tenon type joints locked together with wooden pegs. When all the bents needed for the building were ready, each bent would be 'raised' to vertical and sited as needed and the beams and any braces installed that would link each pair of bents.

The timbers used for the trusses will almost certainly be of the same or similar dimensions to all the other beams in the house and will have been joined together using a mortice and tenon joint. A cutout/recess will also have been left at the apex of the paired truss members to receive and hold the ridge beam and this too may be held in place with wooden pegs.

Almost all the origins of serious structural failures of timber frame houses, particularly very old ones, can be traced back to the joints between the timbers. The wooden pegs used to lock joints together can act as a capillary for rainwater penetration into the body of a mortice and tenon joint and there stimulate wet rot and attract woodworm. All pegs and joints between beams and posts should be regularly treated to prevent water penetration and repaired whenever decay is observed.

To inspect the apex of the truss timbers I would suggest you buy or hire a borescope to view the timbers via small holes - less than 10mm diameter - drilled into the plaster. A cheap borescope can be had for as little as £20.

Sadly, I believe that you have no alternative but to bring down any and all plasterwork, irrespective of its nature, that inhibits free access to the full lengths of both the truss members and their joints. However, on the plus side, the remedial work to re-establish the integrity of the frame, should not require the removal of any of the thatch. The only minor risk to the thatch would result from movement of the battens, ties and/or rods, used bind the thatch to the roof structure. At worst a little 'tidying' of the thatch may be required after all the work is complete.

There should be no problem resting a ladder against the collar tie to facilitate close inspection of the truss apex, unless it and or its joints to the truss members, have already rotted out. Any indications that the collar tie is dangerously weak or its joints to the truss members will become evident after stepping onto the first couple of rungs. If the bedroom floor can sustain your weight while you are carrying a ladder it can probably do the same the other way round with your weight on the ladder.

Regarding the thatch, none of the work I am suggesting requires the removal of any thatch material. From both weight and structure perspectives the thatch is irrelevant and immaterial. As mentioned above, the only damage that may occur to the thatch could only occur due to movement or breakage of a timber batten, a binding rod or the string/wires ties and that risk can be avoided by cutting any nails between the truss members and the battens. Ostensibly all movement of the truss timbers will occur beneath the under-surface of the thatch - the thatch is not heavy enough - even soaking wet - to interfere with that movement.

The brackets I am suggesting are just steel plates bolted to both sides of the truss members. The very crude diagrams below provide basic patterns for the plates I believe could be fabricated to fix the truss members together at the apex and joint the foot of the truss member to the post should such also be needed. The length of the legs in these diagrams are intended to illustrate that these could of any length needed to achieve strong connections to the truss members to resist future rafter spread.

At this stage, and until you settle on a clear plan of attack, I would suggest that installing any props would be pointless unless you believe there is some immediate risk to the house. Happy to offer advice re siting of straps when they become necessary.

I hope the above helps but, as I've commented in an associated post, I am very concerned about the quality of the advice you have been given by your engineer.

 

[Kearn]

QUESTION RE Stapping and Propping. I'm going to strap and prop asap. I will need to identify the posts going into the wall plate so I don't accidentally demolish them making way for straps and needles. Especially on the front wall, kneeling effectively at the top of the wall chipping away plaster and wall infill to be able to see the studs is worrying work given how fragile it looks. I wonder if there is such a thing as a scanner which enbables you to find a timber post in a clay wall?

Try a

QUESTION RE Stapping and Propping. I'm going to strap and prop asap. I will need to identify the posts going into the wall plate so I don't accidentally demolish them making way for straps and needles. Especially on the front wall, kneeling effectively at the top of the wall chipping away plaster and wall infill to be able to see the studs is worrying work given how fragile it looks. I wonder if there is such a thing as a scanner which enbables you to find a timber post in a clay wall?

https://www.flir.co.uk/ depending on how much you wish to spend, I’m still playing with the cheapest iPhone option. Because of differing thermal properties of materials, with practice you should be able to tell the difference with the right settings.

When I surveyed our home we used a far pricier standalone version to sadly discover no timber frame left in a brick addition to our house.

 

[Cubist]

Must admit I had not considered using thermal imaging, I wonder what kind of resolution is achieved? I did think of ultra-sound scanners like those used in hospitals and I see that there are some portable products available on the market... but starting at about £1000+. May be interesting to see how they may perform in life - but a bit much for a tool I may use only once or twice though.

 

[GerryC]

thanks guys and sorry for silence - i'm up to my eyes for a few days but shouild get back to this fascinating stuff over the weekend, ATB and Thanks again

 

[Kearn]

Must admit I had not considered using thermal imaging, I wonder what kind of resolution is achieved? I did think of ultra-sound scanners like those used in hospitals and I see that there are some portable products available on the market... but starting at about £1000+. May be interesting to see how they may perform in life - but a bit much for a tool I may use only once or twice though.

Think it, like most things, depends on how much you’re willing to pay…! Less than a couple of hundred for something that plugs into an iPhone is ok, stand-alone handheld for 4 figures is significantly better. However, both are directionally very valuable. I can write off the cost very quickly just by focussing attention on reducing thermal loss of walls vs windows vs roofs etc by next winter, having just rinsed a full tank of oil in the last 8 weeks in our new project!

Crude pic as I’m still learning the myriad of settings, but the darker blue horizontal above the crosshair is a timber rail encased in lovely modern render…

 

[GerryC]

Hi Gerry,

Indeed I have seen this kind of failure before and in both large and small timber frame structures. Before we acquired this old place I conducted, with occasional help from timber frame specialists, personal assessments of timber frame homes we were interested in perhaps buying. I was also considering building such a house myself and have invested a fair amount of effort in learning about the traditional methods of their construction.

Oddly, I have an example of this kind of truss failure here at Fircroft. Gratefully, this is not in the main house but in an old wood/garden shed in the grounds.

The load spread for your thatcher, even if he were a giant of a man, would typically not be sufficient to produce any significant issues. The bulk of his weight would have been directed down through the rails of his ladders directly to the ground with only a small proportion of his weight then being distributed over a much larger area of the roof. It's also true that the 'common rafters' installed between the ridge beam and the top plate and between the trusses will also have helped to distribute his weight. These common rafters may also have contributed to reducing the overall scale of the damage to your house when the truss or truss joint failed.

Thank you for including this latest diagram giving a cross section view of the house. I had been considering producing a crude diagram to illustrate what I believe the root cause of your problems to be and help me explain the remedial steps. Your cross section view roughly translates into a digram of a 'bent', i.e. a single timber frame of posts and beams which, when joined to other bents via horizontal beams forms the skeletal structure of the building. Typically, the bents would be constructed flat at ground level and all the joints between what will become the posts, beams, trusses and any braces of each bent would have been joined with mortice and tenon type joints locked together with wooden pegs. When all the bents needed for the building were ready, each bent would be 'raised' to vertical and sited as needed and the beams and any braces installed that would link each pair of bents.

The timbers used for the trusses will almost certainly be of the same or similar dimensions to all the other beams in the house and will have been joined together using a mortice and tenon joint. A cutout/recess will also have been left at the apex of the paired truss members to receive and hold the ridge beam and this too may be held in place with wooden pegs.

Almost all the origins of serious structural failures of timber frame houses, particularly very old ones, can be traced back to the joints between the timbers. The wooden pegs used to lock joints together can act as a capillary for rainwater penetration into the body of a mortice and tenon joint and there stimulate wet rot and attract woodworm. All pegs and joints between beams and posts should be regularly treated to prevent water penetration and repaired whenever decay is observed.

To inspect the apex of the truss timbers I would suggest you buy or hire a borescope to view the timbers via small holes - less than 10mm diameter - drilled into the plaster. A cheap borescope can be had for as little as £20.

Sadly, I believe that you have no alternative but to bring down any and all plasterwork, irrespective of its nature, that inhibits free access to the full lengths of both the truss members and their joints. However, on the plus side, the remedial work to re-establish the integrity of the frame, should not require the removal of any of the thatch. The only minor risk to the thatch would result from movement of the battens, ties and/or rods, used bind the thatch to the roof structure. At worst a little 'tidying' of the thatch may be required after all the work is complete.

There should be no problem resting a ladder against the collar tie to facilitate close inspection of the truss apex, unless it and or its joints to the truss members, have already rotted out. Any indications that the collar tie is dangerously weak or its joints to the truss members will become evident after stepping onto the first couple of rungs. If the bedroom floor can sustain your weight while you are carrying a ladder it can probably do the same the other way round with your weight on the ladder.

Regarding the thatch, none of the work I am suggesting requires the removal of any thatch material. From both weight and structure perspectives the thatch is irrelevant and immaterial. As mentioned above, the only damage that may occur to the thatch could only occur due to movement or breakage of a timber batten, a binding rod or the string/wires ties and that risk can be avoided by cutting any nails between the truss members and the battens. Ostensibly all movement of the truss timbers will occur beneath the under-surface of the thatch - the thatch is not heavy enough - even soaking wet - to interfere with that movement.

The brackets I am suggesting are just steel plates bolted to both sides of the truss members. The very crude diagrams below provide basic patterns for the plates I believe could be fabricated to fix the truss members together at the apex and joint the foot of the truss member to the post should such also be needed. The length of the legs in these diagrams are intended to illustrate that these could of any length needed to achieve strong connections to the truss members to resist future rafter spread.

At this stage, and until you settle on a clear plan of attack, I would suggest that installing any props would be pointless unless you believe there is some immediate risk to the house. Happy to offer advice re siting of straps when they become necessary.

I hope the above helps but, as I've commented in an associated post, I am very concerned about the quality of the advice you have been given by your engineer.
View attachment 10410

Hey Steve, finally sitting down for a change after a million small thins last week ... My neighbour who has a hatch into the collar tie has confirmed no metalwork supporting the rafter to ridge joints – he describes "no metal work our side just bits of tree and a few elm looking timber rafters and joists" . I’ve included a pic of the roof from the inside. I tapped it all around and much of it seems to be boarding with some odd sections which sound like they are daubed. Obviously very messy and dusty to open the roof void which won’t have seen the light of day for 20-200 years / remove daub fm thatch, but I would want to have a hatch anyway.

Questions please Steve:

1. Suggestion re borescope good but since I’ll need to remove the collar ceiling (about 14’ x 4’) to access the loose rafter and fit/repair brackets, does it help – I guess it helps makes sure that a rafter is loose before taking all that stuff down?

2. Do I also need to remove all of the inside boarding / infill in the roof entirely or just the areas that cover the suspect rafter and the rest of the rafter-ridge joints?

3. Afterwards I wonder if replacing the collar ceiling is useful or best just to board into the rafters like the rest of the lower ceiling?

I really look froward to your answers, but could I also beg you give me the details of the strapping and needle placement – I’m starting to get edgy about not doing anything to combat the spread and with only a couple of inches in it it’s a little nerve wracking. The way its looking right now, I may decide to build guest accommodation/shed (timber framed!!!) in the garden for us to live in while we do the above work (the front wall infills all coming out too) so would be strapping and propping now, build guest accommodation/shed over the next 4-6 months while refining and discussing plans and then doing the actual repair starting next spring. I’d like to be safely strapped and propped. BTW I’ve looked for contractors to do this work but no joy so far. But the engineer has agreed to supervise me through the work if I have to do it all myself.

(Other bits I hope we can follow up on later ... supporting dormer/rafter during work on front wall, working on / replacing wall plate with such low thatch and the logic of removing wall plate from under dormer and getting the new bit in without it dropping, …. For starters!)

 

[GerryC]

Think it, like most things, depends on how much you’re willing to pay…! Less than a couple of hundred for something that plugs into an iPhone is ok, stand-alone handheld for 4 figures is significantly better. However, both are directionally very valuable. I can write off the cost very quickly just by focussing attention on reducing thermal loss of walls vs windows vs roofs etc by next winter, having just rinsed a full tank of oil in the last 8 weeks in our new project!

Crude pic as I’m still learning the myriad of settings, but the darker blue horizontal above the crosshair is a timber rail encased in lovely modern render…
View attachment 10432

Hi again, thanks for the Flir links ..interesting ... after a couple of sessions looking at and following, I came across the Frankin sensor range ... see https://franklinsensors.com/product-details/prosensor-710-2/ These look a lot lot cheaper than Flir devices which would seem to be great for thermal detection (I'm waiting for my turn on a thermal camera our council lend out to local groups) but i dont see mention of stud/post finding? Any thoughts?
ATB, Gerry Cavander