Brick Infill advice needed!

[xanthe]

Hello all,

I'm new to the discussion forum and hoping that I can find some advice here. Apologies in advance for the long post!

We're in the process of buying a Grade II listed cottage dating from the early 1600's. It's 2 bay timber box-frame with brick infill (originally wattle & daub) and a tiled cat-slide roof.

I enlisted the services of a surveyor who specialises in historic timber-framed buildings and is familiar with the region. I haven't had the report through yet, but I did accompany him when he was doing it so that I could see everything for myself.

Two main issues that came up. The first is that some nice, kind person in the past thought it would be a great idea to repoint in cement - and remortar in some points. Fortunately most of it is literally falling off the wall and so should relatively easy to rake out and repoint with lime.

The second, and more worrying issue is that the infill panels on the gable wall are bowing out and the bricks are standing proud of the timbers - especially since they are only one brick deep and the bricks have been laid in stretcher bond. On the ground and first floor there is plaster-work on the inside of the wall, but in the attic room there is just painted brick. There is a storage area under the eaves on the first floor that doesn't have plaster on the inside and here you can see right through between the bricks in places and there are gaps between the brickwork and the timbers where you can see daylight.

The first and second stories are old tudor bricks and are in lime mortar but pointed in cement, the ground storey is more modern brick and has less issues.
The surveyor said there was significant vibration and he recommends that the majority of the infill panels are removed and repaired and tied in. The bricks are generally in good condition, as are the timbers, so would just be a case of removing them, cleaning them and re-laying in the right mortar in the exact same order that they are at the moment.

So, having had the bad news, the first thing I did was to contact the local Listed Buildings chap who came out to have a look. Initially he said he thought they were fine and not in imminent danger of collapse, but then said that actually a number of panels possibly did need redoing but maybe not. It would have been easier for me if it had been more of a definite yay or nay.

I'm now worrying about whether the panels definitely need doing or not - we may need to negotiate on purchase price and we want to be fair to the vendor, plus as they are the 'original' brick panels I'd rather not do work that doesn't NEED to be done. I worry that a builder may say that work needs doing that actually doesn't and wonder whether I should get a structural engineer before I get quotes.

I was hoping that someone here might be able to advise me on how to tell if brick infill panels are looking decidedly dodgy or if they look okay.

I have lots of pictures if that would help.

 

[Lime]

Get rid of the ivy.

From what I can see from the picture the sections of wall between the timbers are more out of alignment with each other rather than bowed.
Perhaps a few more pictures might be a good idea.

 

[xanthe]

Sorry, had to wait until post approved... more pictures:
Have also had survey through - surveyor says that wall is out of plumb, 3 panels need to be rebuilt due to gaps between mortar and gaps between infill and beams and significant vibration when thumped.

Ivy will definitely be coming off... joyful job removing the dead stuff that clings like mad.

 

[xanthe]

The dodgy panels are bowing in the middle, but was hard to take a picture that shows it well as there is a tree in the way so you can't take a photo straight down the side. Tree has to come out urgently as right next to building.

The bricks are 4" wide and there is nothing but a coat of paint on the inside.

 

[Andys]

We have a house of the same age and type and I do often go round the outside studying the brick infill panels for movement - it's that or lie awake at night worrying! Having said that it can only help to have a couple of conservation builders round to look, with your wallet nailed shut obviously.

Some of our infill panels do stick out a bit in places but a lot of this is due to distortions in the timber frame over the centuries. If a sticky-out panel doesn't show signs of having moved significantly since it was mortared and the mortar looks like it's been there a few years then it might be fine.

For peace of mind I would have thought that some stainless steel fixings to the timber frame and recessed into the mortar would be worth running past a conservation officer. I'm not sure a CO would be keen on the idea of rebuilding wonky infill panels, unless they're actually dangerous.

You say you can see daylight ( between the infill and timber frame?) in places - this isn't necessarily a problem and easily filled with lime mortar ( I've seen one conservator's website which recommends hemp and tar caulking, like a wooden ship :shock: ).

One other thing, your photo shows lashings of mortar around the edge of that protruding panel. We also have a lot of cement mortar and it is a worry that it promotes rot at the interface with the timber so you might need a timber frame expert to do a detailed timber survey, perhaps along with resistograph microdrill tests to check for hidden decay if there are any suspicious-looking timbers ( sounds spacey but it's just a fine drill which produces a graph of the wood hardness along the length of the drill hole )

I found an article on infill panels at buildingconservation.com which might help:
http://www.buildingconservation.com/articles/infillpanels/infillpanels.htm

Andy

 

[xanthe]

Thanks Andy,

The CO was in agreement with replacing some of the panels and bolting them in - he's known to be strict, so his agreeing that some of those should come out and be rebuilt was a bit worrying. The house is in a conservation area and the only one in the road that is G2 - everything else is higher, so I imagine they are fussier than they would be if it was in the middle of nowhere. The wall in question is particularly visible.

The surveyor is a timber-framed building specialist, and reading through the report he is pretty happy with the state of the timbers from what he was able to see - only query (and the CO said the same) is with the timber that is under the tiles and therefore can't be seen.

The panel with the superb ventilation has had a soil pipe and a ventilation system shoved through it and done pretty badly with large amounts of cement shoved round them which hasn't helped the stability. The mortar is old, but all repairs since at least the 1950's have been done in cement not lime and there has been movement since.

There has been a lot of historic movement in the roof and the whole building leans towards the gable - surveyor thinks there may have been another bay on that side and the current external gable wall was originally internal, but the CO disagrees. Surveyor feels that the issues with the infill panels are current rather than historic and that the building hasn't really been looked after properly for quite a long time.

The roof is also not looking too great - lots of spalled and broken tiles and no ventilation or breathable membrane (although no evidence of condensation or damp) and the lead work has been done badly and is deteriorating. Needs a through over-haul.

I grew up in a listed building of a similar age which had to be renovated from top to bottom so I'm not too panicked by most things - but the chances of one of the 3 main walls falling out is not something to take lightly, especially when you have a young child. If you took a good run at the walls in what would be her bedroom I think you might well end up outside as they are some of the ones he's most worried about.

Hope I don't sound like I'm being totally neurotic!

Would a couple of conservation builders be enough or would a structural engineer be a better bet to start with? I don't want to do work that doesn't actually have to be done when it involves messing with the historic bits.

 

[Penners]

Any brick infill panel which moves when it's stressed needs taking out and rebuilding with lime mortar. If you're going to clean off the bricks and re-use them I see no reason to involve the Conservation Office - this is clearly a like-for-like repair which doesn't need Listed Building Consent.

If you have panels which seem sound, but have gaps between them and the timber surround, these can be dealt with by caulking the gaps. You could use lime mortar, hemp and putty or a number of other concoctions that people on this forum have tried (I'm sure they'll let you know).

 

[plasticpigeon]

Wasn't some kind of rope or string traditional???

 

[Penners]

Yes - as mentioned above: hemp.

 

[xanthe]

I brought in the CO as I thought best to check with him what was acceptable before getting a builder round - plus there are a couple of things, like a not very nice dormer window that don't have Listed Building consent. He said he wouldn't be asking for action to be taken, but if and when it needed replacing then something more sympathetic to the building would be good. Also doesn't want any cement that isn't easily removed to be touched for fear of damaging the brick-work.

The hemp stuff looks amazing and there are areas where it could definitely be useful!

 

[Andys]

S'pose there's nothing wrong with a bit of neurosis where falling-over walls might be concerned. Great windows by the way, though perhaps I'm scarred by the endless repainting of softwood frames...

Like you, we had a surveyor who is a timber-framed building specialist who gave us a positive but fairly arm-wavy report full of the usual caveats regarding being unable to investigate anything really useful. As for whether you need a structural engineer or a builder next, I guess you're ultimately trying to achieve a costed, prioritised list of the specific things that need doing - maybe your surveyor is most qualified to suggest what specialisation you need to talk to next. Or maybe a local building-conservation body, or maybe a quick poll of the potential neighbours, even if they are fancy grade1 types, just to see if there's anyone they trust?

 

[88v8]

C17 cottage here. with a mix of wattle and brick infill. Some thoughts.........

Some of our brick is sticky-out, but that's because the bricks are thicker in places than the timbers.
As has been said, unless someone has put fixings through the timbers into the brick, there is probably nothing tying your panels into the frame. The surprise isn't that they're loose, but that some of them aren't loose. After all, the wattle was tied into the frame, but the brick is just sitting there.

If some of the panels need remaking, no big deal, so long as the timbers haven't rotted.
Or, you could replace them with wattle and render, although as you've had the CO round you'd need his permish.

Walls out of plumb, yes, ditto here. Question is why, and whether anything needs to be done about it.
Make yourself a 3D drawing of your timber frame, see whether it has adequate cross-bracing.

What would worry me is rotted joints in the frame leading to loss of structural integrity.

Structural engineer? Unless you're very lucky, you'll just end up with a lot of arse-covering overkill, especially if it's not someone conversant with timber frame buildings.

All this is helpful in negotiating the purchase price of course.

To prevent xanthe junior falling through the wall and making a mess, screw some mesh temporarily over the wonky panels.

On the plus side, you haven't mentioned damp. A period house without damp is a rare and precious thing.

Ivor

 

[Penners]

What would worry me is rotted joints in the frame leading to loss of structural integrity.

I agree with Ivor on this point (and many others!). The brick infill panels don't add much to the structural strength of the building. They're mainly just filling the holes in the important bit - the timber frame. I should perhaps add that, in a box structure, they do also act as bracers, preventing "racking" of the frame.

But a failed oak member is important to the integrity of the building.

 

[Flyfisher]

Interesting point about the in-fill panels and the structural integrity of the building. Presumably the brickwork was not structural when originally built, but compared to close-studded buildings this house seems to have a relatively sparse timber frame and I wonder if the brickwork can become structural elements as the timber frame moves and settles over the years? Or, as Ivor points out, if parts of the frame actually fail.

A panel that moves slightly when pushed is certainly worrying one one level (though probably fairly easily fixed) but could a panel that is rock solid actually only be so because the timber frame has moved or failed in some way such that more weight of the building is resting upon it?

All just amateur musings though and is where an experienced structural engineer should be able to give a more definitive view, but these are the sort of questions I'd be asking.

 

[Penners]

I wonder if the brickwork can become structural elements as the timber frame moves and settles over the years? Or, as Ivor points out, if parts of the frame actually fail.

Yes - I should perhaps have said that the brick infill panels don't add much to the structural strength of the building, so long as the timber frame is sound.

If some timbers have rotted and failed, then it is entirely possible that some of the brick panels have adopted a supporting role.