Attic timber treatment

[Fowler]

Hi All,
I'm new member to this forum and having read some of the threads find it very helpful and informative.
I have just bought a grade 2* listed property so will be asking lots questions.
First up,
I have almost finished clearing the attic and am now thinking of timber treatments, my idea is to treat all the timbers with permethrin treatment and then give everything a second cost of linseed oil and turpentine. I have chosen permethrin over a Boron based treatment because I plan to board out the attic above the insulation layer (CO agreeing of course) and will not have access when this is completed. I have read many good and bad reviews about linseed oil but was would like to know what other forum members think before I commit to anything.
I am planning on treating the external exposed roof timber ends with Creosote ( not nice stuff I know but I have had very good results with this in the past) periodically, has anyone else done this?
Second,
Should I choose secondary single or double glazing?
Any input would be greatly appreciated.
Kind Regards
Steve

 

[Matt Green]

I have almost finished clearing the attic and am now thinking of timber treatments, my idea is to treat all the timbers with permethrin treatment and then give everything a second cost of linseed oil and turpentine. I have chosen permethrin over a Boron based treatment because I plan to board out the attic above the insulation layer (CO agreeing of course) and will not have access when this is completed.

Which insects are you trying to kill?

 

[plasticpigeon]

Hello,

Matt is the expert here!!!

However I will risk an addendum. It is best to make sure that the conditions that harbour rot or insects (damp and warm) don't exist. If the conditions are not favourable to pests then the problem (if you have one) will be solved. Chemical treatments can then be avoided.

Does your property have the original windows? If so you will have to keep them. If not I'm sure your C. O. will advise.

 

[Fowler]

Hi Matt/plasticpigeon,
There are no obvious signs of active woodworm just the usual fly holes, I would guess that the moisture content of the majority of the timbers is lower than that required to support wood boring insects but the timbers near the walls are slightly damp ( I have no moisture meter to check the exact moisture levels). I have found masses of dead woodlice in there ( literally masses!) which suggests to me that there has been some form of treatment/fumigation program carried out in the past but I have also found live ones and this concerns me. The damp timbers near the walls can be attributed to water ingress through the wall which will be dealt with as soon as the funds are available. In the meantime I need to get some insulation in the loft so that the heating bill doesn't cripple me in the winter. I am only concerned with the timbers that will end up between the lower ceiling and the boarding, if possible I do not want to have to lift this in the future to check for activity. The remainder of the timbers (the ones above the boarding) can be monitored on a regular basis as there will be easy access to them.
I have found woodlice hiding in crevices within the walls but in time these will be re pointed and rendered (lime mortar). Should I treat the stonework to sterilise it?
As for the linseed oil and white spirit/turps application, rightly or wrongly I feel that timbers should be treated (dad used to make us treat all timbers both inside and out on our yard when I was younger) and found this to be a regularly suggested potion and has good reviews in many places.
The current windows will have to remain but my CO is happy with a secondary solution provided they are not visible from the outside. I am not overly keen on the standard form of secondary glazing and was thinking of devising a new system that is more pleasing to the eye.
From the research I have done so far it indicates a build date of about 1579 but I dont believe the windows are of that period.
Kind Regards
Steve

 

[JoceAndChris]

Windows need to be right for your building, and as it's got that star, it's decided by EH not the CO as far as I know. It's very difficult to get the right skinniness on the glazing bars with double glazing, and chunky ill proportioned windows often spoil lovely old facades.
But if you have mullions I heartily recommend bronze casements made by Vale right here where I live. They're beautiful things and very insulating being double glazing!
But if they're sashes secondary is better.

Thick curtains are worth investing in too, with proper interlinings.

 

[Zebra]

Well, I'm not listed, so can't comment on that aspect, but I as far as linseed oil is concerned, I don't think it can harm your timbers. If they're old and dry, they'll lap it up. It will change their colour though. I've used it here and my beams have gone from a pale and faded brown to a rich dark brown.
Nor, in my opinion, would I hesitate to use an interior wood treatment, though others may disagree. I'd hesitate to apply a preservative, because it would be so difficult to ever remove in future, but an interior wood treatment which basically consists of white spirit with 0.1% pemethrin and an even smaller smidgeon of something I can't possibly spell, I wouldn't see the harm in, and would offer you peace of mind.

 

[Flyfisher]

Welcome to the forum Fowler.
Splashing preservatives around is a personal decision and much will depend on the type of wood and it's condition. My instinct is not to do so, though I have used Cuprinol 5-star in a few specific areas. We have many exposed oak timbers that are still rock hard after 400+ years, so I'm extremely sceptical that spraying them with preservative is going to make much difference now!

Matt is our resident science professional when it comes to wood eating lifeforms and the general view seems to be that most wood is indigestible unless it has a certain level of moisture. So if there is a damp problem resulting from a structural problem (leaking roof, dripping gutters, etc) then THAT is the thing to deal with first rather than try to prevent rot or worm when the environmental conditions are so perfect for them. Take away their preferred environment and they'll likely move on to somewhere else or simply become dormant and do no more harm.

. . . . and as it's got that star, it's decided by EH not the CO as far as I know.

That's an interesting point. Having been sat on the sidelines while our CO and EH 'had discussions' over our G2* kitchen extension, it doesn't seem to be the case that EH has an automatic veto or can simply 'pull rank' on the CO.

However, my understanding is that G2* applications MUST be passed to EH for comment and they can also appeal to the Secretary of State (who will almost certainly side with EH), so I guess the trick is to be sure of the merits of the case in question so that EH can find no justifiable grounds to refuse - which will require a very good CO.

As ever, each case is unique, so it's difficult to argue with precedents. I'd suggest that the best thing by far is to team up with the CO and put the well being of the house first - once that relationship is in place and working well, everything else will likely flow naturally without too many problems.

 

[rogerh]

Thick curtains are worth investing in too, with proper interlinings.

Or shutters (when appropriate).

 

[Moo]

I'm really surprised.
Nobody's asked for pictures!

 

[worms]

I have found masses of dead woodlice in there ( literally masses!) which suggests to me that there has been some form of treatment/fumigation program carried out in the past but I have also found live ones and this concerns me.

If I were you I wouldn't stress about woodlice! I'm typing this during a temporary stop-over in an unoccupied 1880s building that hasn't been hoovered since I was last here about a month ago and I am surrounded by woodlouse carnage - got to be 100 dead ones on the kitchen floor alone! I am pretty sure the house is not about to fall down and will still be here (with a new crop of woodlice) when I next visit.

I certainly wouldn't be using dead woodlice as evidence either of past treatment or the need for future treatment.

 

[Fowler]

Joyce and Chris
The windows do have mullions so it will be easy to hide the inner glazing joint and the window openings themselves are considerably wider on the inside so there is plenty of scope to hide the frame. I would never want to change what is there as I absolutely love the look of the current windows but I have to make the place as economical as possible to live in. I have looked at Vale Right and they seem to have a variety of options for this.
We will be going with curtains as the easy first step but if possible we would like to have shutters as the permanent choice as suggested by rogerh.
Zebra
My only concern with Pemethrin is the toxicity, given that I am going to use it strategically and not plaster everything “willy nilly” then I agree, the peace of mind is worth it. If I get issues with the easily accessible timbers I will be using a boron based treatment even if this needs to be re-applied in the future.
I am not concerned with the aesthetic look of the timbers so the linseed treatment will never need to be removed however I am aware that in essence I am only the custodian of the building for the time I own it and don’t want to give future owners a problem. Your post has given me some peace of mind in the use of the linseed oil option.
Hello Flyfisher,
I have read in numerous other posts on various forums that suggest that the only real requirement for roof timbers is to keep them dry and bug free, however, I have this niggling urge from past experience to put something on there and feel that I will then be able to sleep at night (I hope you can understand this). The roof has been replaced at some point and is now a mix and match of what look to be old (but not original) and new. If treating the timbers will have a detrimental affect then I will just stick to keeping them dry and take some sleeping pills. Lol.
As mentioned before, the dampness in the edge timbers will be resolved in due course but I simply don’t have the funds to do this right now.
Not wanting to sound ignorant EH?
I believe I have a very unique relationship with my CO (nothing underhanded), our proposals (verbal at this point) will not alter any internal building fabric or exterior features and she is very happy with this. It used to be a pub and a restaurant and she really wants it to be returned to residential use as, in her opinion, it will receive greater care and sympathy.
Hi Moo,
How do you upload pictures? Or just look up “The Penllwyn Manor”
Hi Worms,
Would it be correct to assume that the woodlice got in there and thrived when maybe the attic space was wet then? I have no fear of the little critters but I’m not sure my partner and the two girls would say the same. I would just like to prevent a “population surge”.

 

[Matt Green]

There are no obvious signs of active woodworm just the usual flight holes, I would guess that the moisture content of the majority of the timbers is lower than that required to support wood boring insects but the timbers near the walls are slightly damp ( I have no moisture meter to check the exact moisture levels).

Hello Steve,

You have a common paradoxical problem: the sections of timber most at risk from wood boring insect activity are the ones you can't get to (they are embedded in or butted to walls). The timber being dry is preservation enough and I would not undertake further treatment, instead:

The damp timbers near the walls can be attributed to water ingress through the wall which will be dealt with as soon as the funds are available.

I would save the treatment money and spend it here instead. Addressing the leak is the best timber preservation possible as dry timber is not at risk of attack. This is the best advise I can give.

In the meantime I need to get some insulation in the loft so that the heating bill doesn't cripple me in the winter. I am only concerned with the timbers that will end up between the lower ceiling and the boarding, if possible I do not want to have to lift this in the future to check for activity.

I wouldn't worry. As long as they are dry they are at no risk.

I have found woodlice hiding in crevices within the walls but in time these will be re pointed and rendered (lime mortar). Should I treat the stonework to sterilise it?

Good grief- no. Woodlice are not a structural issue.

As for the linseed oil and white spirit/turps application, rightly or wrongly I feel that timbers should be treated (dad used to make us treat all timbers both inside and out on our yard when I was younger) and found this to be a regularly suggested potion and has good reviews in many places.

It depends entirely on the quality of the timber and where it is. Good quality slow grown timber is really durable and will last for decades and decades with no treatment. Cheap fast grown softwood fence panels with soil against them and a gutter running off at one end are a different matter entirely. Most of the timber preservatives used on what would otherwise be dry timber at low risk of decay are applied unnecessarily- the customer is often paying for peace of mind.

Cheers,

Matt

 

[Fowler]

Hi Matt,
Thank you for your comments/advise. There are timbers that sit in the wall that is damp and I will remedy this as soon as I can, however, the wall will require some time to dry out and finding the source can take a while if there is nothing visibly obvious. I am going to remove the plaster from the wall at ground level and put a dehumidifier in the room to see if this helps.
The timbers are of varying types and ages so I will take your advise and steer away from permethrin treatment but give everything a few coats of the linseed oil/white spirit potion.
As for the woodlice, they may not pose a structural risk to the timbers but they pose a serious threat to my ears when the little blighters fall in miss Steves soup. lol.
Thanks again Matt, your advise is very much appreciated.