Timber-Framed home owners

[Anonymous]

I am searching for owners of old timber-framed buildings (purchased within the last five years) who commissioned a full structural survey prior to purchase, but who have had to carry out major reconstruction work since (not just cosmetic). I am researching whether todays full structural surveys are providing homebuyers with vital information about the damaging effects of cement render, concrete flooring and vinyl based paints within their reports.

 

[Anonymous]

What is the ultimate aim of your research?

 

[Anonymous]

I have lived in a 17thC timberframe cottage for the last 15 years. We have the dreded concrete render outside and concete floors inside. The cement render had small cracks on one of the end walls the rest of the walls are fine. On reading posts about lime here last summer I decided to hack off the nasty cement stuff fearing I would see suffocated soggy rotting timbers. Well I had a pleasant surprise all the timbers were bone dry infact they look as good as new, I drilled into them to make sure and they are all fine, The sole plate is also bone dry. I replaced the render with sheep wool insulation breathable membrane and weatherboarding ala MIDDI, as this is a traditional covering in our village. Following this I chisseled holes in the rest of the walls to check the condition of the timbers I could not find any problems. I also have no sign of damp inside the cottage.

I have the certificates from the previous owners who had the cottage re-rendered 25 years ago, the render it replaced was a 1950s concrete and pebbledash job.

Now I do not advocate or champion concrete or cement, they are unforgiving materials. In the renovation on old cottages traditional materials should be used they are more appropriate and environmentally sensible, however in my village there are lots of timerfame cottages and none have lime render, so if they all hacked off the cement think of the landfill and environmental damage/landfill.

I was worried to death by all the post on here about the damage the cement could be doing to my cottage, so I took action only to find no problems at all. I guess I am lucky
but my fears were costly

 

[Anonymous]

I agree with David.

It is not clear what you are looking for.

As to "full" structural survey and timber framed houses totally covered in any render, for example, is near impossible for a surveyor to distinguish his A""E from his elbow as to the condition of the timber frame.

Cement in itself used as an exterior render will not have a deterimental effect to the timbers, especially if these are exposed internally so the breathing mechanism is not impaired. The major reason why is not compatible with timber framing, long term, is because the frame expands and contracts and cement does not.
The cement based render will inevitably crack allowing unseen water entry which will trickle gently down the studs onto the sole plate.

The long term damage of timbers can be devastating.

Rich lime renders are much better but not the ultimate solution , as these eventually will also crack and repairs is the norm .

It is my opinion that the best way to conserve a timber frame ( not necessarely to everybody's taste) is to clad it with feather edge planks, onto a breatheable menbrane and spaced at least 1inch from from the original timbers externally.

As to cement foors, correctly applied will not cause any damage to the building, this is more an enviromental issue.

Modern paints, glosses etc..?.
I cannot think where you could use them on an Oak frame buiding.

 

[Anonymous]

A wise person once said there are 2 kinds of concrete, that which has cracked, and that which is about to crack. Same applies to all cement mortars. Now, you have a thininsh layer of crete on wood, ie a gross difference in expansion coefficients Cracking is inevitable, the question is when.

And what happens when its cracked? Water gets in, but doesnt evaporate out, so wood often rots.

You did the right thing by checking. Maintenance costs money, but is cheaper than replacing sections of rotten wood frame later.

Cemented wood frame brings a risk of rot, not guaranteed rot.

NT

 

[Anonymous]

Bravo, Middi! The voice of sanity and calm reasoning.
As you point out, lime renders are inherently more forgiving to timber-frame movement than cement renders - but they'll all crack in the end. Wood can flex and move - hence wood-on-wood works best.