Seeking Advice: Cement Render on c.1600 Timber-Framed Cottage

[esherhouse]

Hi all,


I'm hoping someone here can offer some insight. We've just had a Level 3 survey carried out on a timber-framed cottage, believed to date from around 1600. The surveyor found no structural defects—no bulging, no signs of movement, and no damp on the internal faces of the external walls. The roof and windows are in good condition, and there's a new boiler in place.


The main concern raised was the external render. The surveyor believes that three sides of the house—the front elevation and two gable ends—are timber-framed and currently rendered with cement. He noted some hairline cracks on the front elevation. He also mentioned it might be NHL 3.5, but is leaning towards it being cement. In our follow-up call, he said the render would likely need replacing within 1–2 years and advised having £100k available to cover potential costs.


I asked for photos of the cracks, and honestly, to me they are barely visible. I've attached those along with a couple of general exterior shots. My husband is ready to walk away based on this, but I’m more on the fence. I understand that cement render on a timber frame isn't ideal and would eventually need replacing, but given the lack of damp and other visible issues, I’m surprised by the urgency and scale of the recommendation.


I've reached out to a few specialists for second opinions, but I’m not sure if I’ll hear back in time.


Has anyone else faced a similar situation? Is it likely that the render would need replacing so soon, despite no current signs of internal issues? I’d really appreciate any thoughts or experiences others can share.


Thanks in advance!

 

[jamest]

The problem with these kinds of places is that you can never be sure about the condition of the timber frame without inspecting it, preferably from all sides, but minimally from inside and outside, which is impossible because there is render in the way.

If the render is indeed cement, then water can and will get through the cracks, however small they may be. There's no easy or guaranteed way to stop this - if you try filling them, they will open again and/or new ones form as the timber frame moves with the seasons. Once the water is in, it's hard for it to get out (cement render isn't very water permeable, except through the cracks and its impermeability won't be helped by any modern plastic masonry paint that's been applied to it) so there will inevitably be some rotting of the frame. The fact that there is no sign of damp internally isn't a guarantee that there is no moisture behind the render. The question is, is any rot damage of structural significance? The answer won't become clear until the render's off. If extensive frame repair is needed, it can be very expensive. You might be lucky and the frame isn't structurally compromised, but then you might not be - no surveyor can tell you without removing the render, it would just be guess work (though informed, one would hope, by previous experience with similar buildings). The fact that there are no signs of structural defects is no guarantee that there aren't any - these old timber framed buildings can be remarkably robust.

I don't know why the surveyor gave you a 2 year time frame to remove the render, but I guess the sooner the better. There are cement rendered timber framed buildings around where I am that have been that way for decades, many of them (probably all of them) slowly but surely deteriorating without any obvious, visible signs.

If you want to have the bejesus scared out of you, try searching on YouTube for Peter Ward's videos of the kind of damage that can happen to old timber framed buildings.

 

[esherhouse]

This is very helpful, thanks.

 

[Cubist]

Sorry to be the bearer of additional unwelcome news but external render and for that matter internal plaster coatings of timber frames can be very bad news insofar that these can trap moisture in the frame to induce rot, Typically this occurs near the foot or base of the frame as gravity will carry the water to the lowest available levlels, This house has an increased risk of rot damage to the frame as its cill plates are all sited at or very near ground level. In your shoes I would want to see an invasive survey of all the cill timbers and the main corner posts before considering making an offer.

 

[esherhouse]

Thank you for taking the time to respond. We had already made an offer, which was accepted, and the mortgage was approved—so the survey was the next key step. While we were hoping for better news, I’d rather have the facts now than face surprises later. I really appreciate your helpful input.

 

[Alex_]

Use the survey to negotiate a discount if your heart is set on it. I doubt you'll get £100k off, but half that might be achievable. That property looks of a type that you get round here so the risk of problems will be well understood, at least on the estate agent side of things so they might advise the seller to consider it.

 

[esherhouse]

Sorry to be the bearer of additional unwelcome news but external render and for that matter internal plaster coatings of timber frames can be very bad news insofar that these can trap moisture in the frame to induce rot, Typically this occurs near the foot or base of the frame as gravity will carry the water to the lowest available levlels, This house has an increased risk of rot damage to the frame as its cill plates are all sited at or very near ground level. In your shoes I would want to see an invasive survey of all the cill timbers and the main corner posts before considering making an offer.

Sorry, I have a follow up question about this. I was looking over the survey again and it says this:

"The external walls of the original building are of timber framed construction on a brick plinth and
rendered."

Does the brick plinth sit on top of a sill plate?

Many thanks

 

[esherhouse]

Use the survey to negotiate a discount if your heart is set on it. I doubt you'll get £100k off, but half that might be achievable. That property looks of a type that you get round here so the risk of problems will be well understood, at least on the estate agent side of things so they might advise the seller to consider it.

Thanks. It is in a location that works really well for our family, so this is good to know and something to think about.

 

[Stevers]

Does the brick plinth sit on top of a sill plate?

The cill plate will be on top of the brick plinth.

 

[Cubist]

Sorry, I have a follow up question about this. I was looking over the survey again and it says this:

"The external walls of the original building are of timber framed construction on a brick plinth and
rendered."

Does the brick plinth sit on top of a sill plate?

Many thanks

No, the cill plates sit immediately on top of the brick plinth. This is the common approach to isolate the timber from the ground below as far as possible and to limit the possibility of damage from rising damp penetration. Depending on when the house was constructed or perhaps significantly repaired/restored in the past a slate DPC or more modern material may have been installed beneath the cill plates to further protect them. Where the cills are close to ground level you would be wise to check and if need be reduce the height of the surrounding ground and keep vegetation growing close to the walls as low was possible if not non-existent.

 

[Kearn]

No, the cill plates sit immediately on top of the brick plinth. This is the common approach to isolate the timber from the ground below as far as possible and to limit the possibility of damage from rising damp penetration. Depending on when the house was constructed or perhaps significantly repaired/restored in the past a slate DPC or more modern material may have been installed beneath the cill plates to further protect them. Where the cills are close to ground level you would be wise to check and if need be reduce the height of the surrounding ground and keep vegetation growing close to the walls as low was possible if not non-existent.

Sole plates can happily rot from the underside if the plinth has been incorrectly pointed in cement or worse, rendered inappropriately.

I have the scars to prove it - stable looking timber on top and both sides, yet the underside was mush from the moisture being trapped under the plate on top of the stone plinth. Our moisture would have entitled form rain but also ground water tracking up due to our conditions.

If you can’t see all four faces of a timber, you never really know its condition. Seeing no faces of the timber is a total gamble.

 

[Kearn]

I’d be interested to know why he ‘believes’ it to be timber framed, and on only 3 elevations?

It either is or it isn’t. But that can only ascertained through seeing the frame on at least one face.

What does the inside look like? I’m guessing gypsum plaster over the frame everywhere?

That in itself, especially if tanked beneath, can mask the actual damp issues going on behind the scenes. Not seeing damp doesn’t mean there isn’t any.

 

[esherhouse]

“The walls of the original cottage are timber-framed, and the rear addition is of solid masonry wall construction.”

The extension is from the 1800’s and the whole thing is rendered. As I understood it, the cement render on the front and gable ends is extra concerning because of the timber frame, but it would all need to be replaced.

I don’t have a great close-up picture of the inside walls, but I can attach a still from a video.

 

[jamest]

Looks as if the construction is very similar to my previous house: a timber framed cottage with a single story, later brick extension that extends the whole length of the rear elevation. This gives you a catslide roof at the rear and the original rear wall that was once external is now internal - that's consistent with the 3rd of the original photos and the surveyor's statement. Sound right? The photo above looks like a ground floor interior wall, probably doesn't matter too much what that's plastered with, but it's impossible to tell from a picture - rather uneven plastering, but that doesn't really help!

 

[esherhouse]

Yes, that's exactly right.

 

[Mrs McG]

My cottage is also from 1600s, cement render on a timber frame with later additions up to 2024. You wouldn’t ever choose to use cement render but if it’s there already then it’s not necessarily a live problem. The risks are increased but not inevitable. My surveyor said the render on my cottage was stable, in good repair and the cottage showed no signs of damp. If I had the money spare to remove it I would, but in the meantime I’m leaving well enough alone.

 

[Stevers]

Alway best not to fix what isn't broken. There must be quite a few 'cement' renders that are actually cement/lime at 1:1:6 or even 1:2:9. They should perform better than a pure cement render. Even if not ideal they might be 'good enough' for the prevailing conditions.

 

[esherhouse]

Thanks, Mrs McG and Stevers. Really appreciate your thoughts. I think I’d feel a lot more comfortable going ahead if I knew we could safely hold off for five years or so to build up a bit more of a financial buffer before tackling the render.

The surveyor’s initial suggestion was to rake out the existing render and seal the hairline cracks as a temporary measure, which does sound more manageable in the short term. That said, I have no idea how viable that really is and the thought of the timbers rotting away in the meantime is pretty unsettling.

 

[jamest]

My previous house that I mentioned in an earlier post was in a very similar state to yours (or better 'not yet yours') and I did exactly what your surveyor suggested - raked out the render along the hairline cracks and then filled the resulting, much larger 'crack' with a filler. I used Toupret Fibacryl because it claimed to be flexible and good for this sort of thing. It lasted pretty well for the rest of the time I lived there, maybe 4 years, and I was lucky in that no new cracks appeared.

The plinth on that house looked similar to yours - painted black. It was a bituminous kind of paint and for that reason I stripped it all off, repointed the bricks in lime and repainted with Ingilby's exterior 'blackish' limewash (which I can thoroughly recommend for these kinds of jobs). If you can get the plinth breathable both inside and out (and make sure the ground levels are 6 inches or so below the level of the subfloor), you've already done a lot of good that will slow down any rotting to the base of the frame (assuming there's any of it left).

Oak tends to rot very slowly and these kinds of buildings can be pretty robust. Obviously, I moved out so didn't have to face the prospect of stripping the render and repairing the frame. Had I done so, I probably wouldn't have bothered repairing the frame on the ground floor, but just rebuilt the offending bits of wall in brick as the house wasn't listed. If it had been listed, then repair of the frame would have been unavoidable.

 

[Bobby]

Hi there,
We also have a timber framed building around 1800s, thatch. When we bought it 20 years ago we had issues during the survey as they discovered it was cement render. It is on a brick plinths and has a ‘bell curve’.
After lots of back and forth, we got a second opinion and they suggested it was in pretty good condition and the bell curve was sufficient to keep moisture away as long as we kept up with any cracks.
20 years on and we have never had any issues with damp beams/timbers or the render.

We are now looking to sell and worried the same issues are going to arise.
Any rearrange would be good!!

Back to the main thread though, and I am so happy we didn’t pull out of the sale. It’s been the most fantastic family home for us!