realising the extent of the work....starting with timber

[glayzell]

some of you may have read that i am embarking on the restoration of C18 timber framed semi.

I had the floor boards up today to find that in one room someone has relplaced the joist ends, but strapped 4x2's to the original 6x2's...at least they have replaced the wall plate in that room.

In the dining room i got under the void in the floore to havbe a look to find that all the joist ends, the wall plate and the timber uprights are rotten at the bottom.

The building is G2 listed. i spoke with my uncle whois a builder. He suggested building brick piers, putting a 8x2 on top of them, repairing the ends and resting the newly repaired ends on the 8x2, thus avoiding contact with the original wall. he said this would avoid the same thing happening again.

Secondly, i want to explore the true extent of the the rotten timber in the walls, this will mean carfully hacking of the existing laths and plaster.

i guess my questions are, a) is there any sense in my uncles suggestion, which i assume will need LBC, if not any tips? b) can/should i go ahead and carefully take the plaster of the walls before speaking to the CO as it will be a like for like repair?

oh, also, any tips for lifting tongue and groove floorboards without causing damage to them? the ones i lifted today were either rotten or had been up before.

 

[middi]

This is your "unfortunate" opportunity to investigate the damage on the sole plate, the floor joists and the wall studs , and make a good repair.

What your uncle suggests goes some way towards repairing the floor but still leaves you with a problem of the sole plate and the studs.

The correct way is to initially expose the wall internally about 200mm above the floor or sole plate level, this will allow to evaluate the real extend of the rot.

You can inform your CO, preferablly before you start your rot investigation, and then explain the course of action you intend to take. If you are destructive in your approach you can be sure he/she will let you know.

The idea is to repair and replace, as existing, any rotten wood which you may discover. Presumably oak in an 18th C. cottage .

Please bear in mind that if the sole plate and wall studs are of oak construction they may not be as rotten and unserviceable as even a good builder may think. Someone that understands these old oak buildings may save you money.

 

[glayzell]

Thanks for your comment middi.

The building is not a cottage, it was originally a double fronted town house, but was 'cut' in half following a fire about 100 years ago. The timber frame is entirely softwood.

 

[Penners]

As I understand it, your uncle is going to repair the rotten joist ends, and then support these on additional 8 x 2 joists at right angles underneath.

This seems a sound idea, except that I'm not sure about placing the new joists underneath the repaired joist ends. As you have discovered, this is the part of the joist most susceptible to rot, and although the additional cross joists may be protected from rot by being isolated from the brick foundations, they won't be much help if the ends of the original joists (that are bearing on them) rot again.

I think I would move the new cross joists in a bit, to take them away from the likely rot area. And I presume the support piers will have dpc's in them? (I'm probably insulting your uncle by asking that question!)

 

[glayzell]

the thinking is, instead of the new joist ends (which may end up 2m long) going back into the wall and sitting on another wall plate to rot again in 40 years, they will stop just short and will be supported on piers with a dpc independently....

...will this need lbc?

regarding the wall timbers, is it better to cut back the dead wood and piece in new sections or do as i am with the floor and strap new timber for the full length alongside the old stuff???

 

[middi]

As your wall studding is constructed of softwood the chances are that the rot in the sole plate and studs is probably more extensive than one would find on a similar oak construction.

You certainly need to remove all the rotted and infected wood and burn it, cut well into the sound wood and treat for insect and fungal disease.

Use pretreated timber for the sole plate and studs and use this opportunity to install a DPC below the plate.

As to the actual repair of the studs, you can certainly repair these by splicing new wood on existing but it would be much stronger if you can insert new studs beside the existing and bolted or screwed toghether, it much depends on the carpenter that is carrying out the repairs as to how it is best repaired.

As to the floor joists I would simply use galvanised joist hangers attached to the sole plate to carry these, quicker and cheaper.

I would not think that the CO would object to this approach, nevertheless in an ideal world he/she sould be informed first as they may want to satisfy themselves that any other historical fabric is not damaged or not replaced during the process of repair.

This repair done correctly should outlast the rest of the other timbers in the house.

 

[Matt Green]

As your wall studding is constructed of softwood the chances are that the rot in the sole plate and studs is probably more extensive than one would find on a similar oak construction.

That depends on the softwood. Good quality softwood is very durable indeed. The types of decay fungi might be a bit different though.

You certainly need to remove all the rotted and infected wood and burn it, cut well into the sound wood and treat for insect and fungal disease.

The chances of dry rot in softwood soleplate are slim to none, it prefers an easier meal. It's not a great specification for dry rot work anyway.

You don't need to burn the decayed wood. It's not a biohazard. Cut back to sound timber and brush treat the exposed ends with a spirit-based preservative. Isolate with a DPM.

Other than that: seems fair.


Matt Green
-seeking out fear of dry rot and thwarting it wherever he can.


I should get one of those bat signals with a fruiting body picture to reflect on low cloud. "What? An overly zealous specification!? Quick! To the rot wagon!"

 

[Nemesis]

If you insist on using small print can you use large small print?

 

[Moo]

I have a facility on my keyboard that enables me to enlarge/reduce typescript to suit my failing eyesight. A great boon.

 

[Penners]

If you insist on using small print can you use large small print?

Nemesis - do you have a wheel mouse? If so, hold down the Control key while you roll the wheel of your mouse. You should find that rolling it one way will reduce the type size of wbsites and the other way will increase it.

 

[middi]

Matt, thanks for the clarification from an expert point of view as to how better understand wood rot.

It is nice to obtain expert advise free, normally when these kind of repairs are executed a lot of common sense comes into play and further expense on specialist advise is not always sought. My advise was solely based on method of repair and broad approach in dealing with rotten softwood timbers.

I am sure all these comments will serve Glayzell well.

 

[biffvernon]

I should get one of those bat signals with a fruiting body picture to reflect on low cloud. "What? An overly zealous specification!? Quick! To the rot wagon!"

 

[Nemesis]

I do have a little thingy which allows for larger print - but first thing in the morning I need large small print large so it can be enlarged more.

Erm...

Thank you Mr Vernon, very kind.

 

[Moo]

9.03 = first thing in the morning?

 

[Nemesis]

Depends. Some morning my eyes work sooner than others.

 

[Nemesis]

If you insist on using small print can you use large small print?

Nemesis - do you have a wheel mouse? If so, hold down the Control key while you roll the wheel of your mouse. You should find that rolling it one way will reduce the type size of wbsites and the other way will increase it.

Penners - I tried that and the whole thing locked up!

Oh well.

At least Microsoft has a new error report to play with.

 

[David Dyer]

If you're using IE7 it seems to work sometimes but it can be very slow never had it lock up though.

 

[glayzell]

thanks everyone for your advice, i plan to call the co tomorrow and have a chat, he knows the house and has a real interest in it. I love the house, but his enthusiasm for it is quite frankly worrying!

Personally i would prefer to strap new joists to old and put them on hangers...

I did some exploration and drilled a hole through the plaster with a mandrel to look at the most rotten stud i have found and by 2 feet up it is sound...i have found some wood worm in places, bu this seems quite isolated. i am not overly worried about it all, i expected the worst and thus far it has not been that bad.

 

[Penners]

If you insist on using small print can you use large small print?

Nemesis - do you have a wheel mouse? If so, hold down the Control key while you roll the wheel of your mouse. You should find that rolling it one way will reduce the type size of wbsites and the other way will increase it.

Penners - I tried that and the whole thing locked up!

Did your mouse come with device driver software? if so, are you using it, or are your relying on the generic Windows driver?

If the latter, you might find it will behave better if you install the driver that came with the mouse - or download the manufacturer's latest driver.

 

[Moo]

It's threads like this that make me really grateful to have a Mac and its own built-in internet browser.