Rotten wood in roof crowsfoot

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1895BrickConversion
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Rotten wood in roof crowsfoot

Post by 1895BrickConversion » Sat 12th Jun, 2021 9:53 pm

Our roof has crowsfeet.

On my summer jobs list was one that I'd identified as looking a but iffy over winter. Its actually not a crows foot, but the wood that sits under them and rests on top of the brickwork. I'm not sure what this is called.

So I stripped the end of it back and clearly it has seen some filler before, mainly at the top. I decided to dig out the rotten wood to see the state of it. The (relatively small in diameter) hole at the bottom right probably goes 4 to six inches deep. There's a point on the bottom of the wood about that far in that, when you tap on it, it doesn't sound right. My assessment is that if I dug upward at that point I'd be able to connect with the hole I've dug in from the end.

The wood that's coming out of this rotten bit has a similar look to rolling tobacco.

So, what should I do about this. What's the correct way to handle it. Would a future fix be likely to be materially worse / more expensive if it filled it and painted over for the time being?

Photos:
tinyurl.com/2d8a6b9c

Thanks
Steve

Feltwell
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Re: Rotten wood in roof crowsfoot

Post by Feltwell » Sun 13th Jun, 2021 12:10 am

First off, I'd strip all the paint off, take the filler off and go over it with a bradawl and find out just how rotten it is.

Having messed about with many timber repairs over the years, I find most success through cutting out all rotten timber and splicing in new sections with epoxy. Dowel jointing is good, better than using screws, keep metal out if you can. Getting rid of all rot is key, wood hardener and filler is a temporary fix at best.

This old thread of mine might help - nearly a year on, all the repairs shown have held and all still looks good.

viewtopic.php?f=1&t=16977&hilit=epoxy

Future "proper" fix versus quick repair now? Depends if that quick repair would halt the current degradation or not, which generally means would it keep water out or not. Plus of course if the timber is structural or not. Fill or paint over rotten timber and the repair will fail in time, that much is guaranteed, but it's hard to say how long that will take.

Edit - just managed to see your pictures properly. So it looks like that timber is the end part of the wall plate, and it's the only thing that is supporting the exposed end rafter. It looks like it's a key part of the supporting structure, which changes the approach somewhat. I'd say you need to investigate the rot thoroughly from what you can see back along the wall plate. Until you've stripped it back, you just won't know - it could be a simple cosmetic repair to the exposed end as there is enough decent timber left to be supporting the end rafter, it could be that the end section of wall plate needs replacing completely, in which case it will be tricky as ideally you would need to make the joint well back along your wall and the rafters will require temporary support - but - if that's the case I do wonder if the exposed decayed end could be cut off and a new section joined on just for the end rafter with heavy stainless steel dowels epoxyed inside - it has to be a structural repair.
Last edited by Feltwell on Sun 13th Jun, 2021 7:17 am, edited 3 times in total.

Feltwell
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Re: Rotten wood in roof crowsfoot

Post by Feltwell » Sun 13th Jun, 2021 7:01 am

. double post

MatthewC
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Re: Rotten wood in roof crowsfoot

Post by MatthewC » Sun 13th Jun, 2021 9:30 am

In your third photo - the one showing the side view - what is it that I can see on the wall plate about 3" along to the right from the corner of the brick work? It looks like a metal plate and it worries me that something might have been done with the end of the wall plate. As Feltwell says, that end is structurally important for the gable and it's not the place for someone to have done a bodge! Hopefully it's not as bad as I fear...

Matthew

88v8
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Re: Rotten wood in roof crowsfoot

Post by 88v8 » Sun 13th Jun, 2021 10:18 am

Doesn't look too bad at the moment, barge board not dropped, verge not cracked, but If you leave it, eventually the barge board will drop and water will get on top of it and that will rot. Then you'll have a major repair to do, and still need to do the original repair.

So yes, the end has to come off, back to about one brick in if it's sound there.
Splice in a new piece of wall plate.

Simple enough repair, if it weren't for the roof being in the way. Scaffold, props, tarp...
Bungalow?
Buy some spare tiles before you start, especially one-and-a-halves for the verge.. salvage yard....

It's rotted because at some time, painting has been neglected and rot has got in through the endgrain. If there are similar features elsewhere you might take a look at them as well.

It's a pain to find stuff one wasn't expecting... been there...

Ivor

1895BrickConversion
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Re: Rotten wood in roof crowsfoot

Post by 1895BrickConversion » Mon 14th Jun, 2021 5:21 pm

Thanks for the considered responses each of you.

Yes, it is structural I agree. Interesting idea of using some large / long stainless dowels to joint the two sections Feltwell. I'll raise that.

Speaking of which, Ivor, the job you describe doesn't sound too bad. Would I need a roofer specialising / experienced in older buildings, or would any competent roofer be able to do this. I suspect the latter? And how long would it take - it is on the lower floor of the building - I can reach up and touch it easily, so no scaff required. Is it a day or two of a job for a competent person, or do I underestimate it?

And, depending on the answer to the above, does anyone have a recommendation for a person in the Essex area? This might be in range for me if I had unlimited time and a clear plan to work to, but between working and family, that's not the case.

And Ivor, when jointing the wall plate, is that "one brick in" one brick lengthwise presumably? What would a traditional splice take the form of - if not Feltwell's butt-up and super dowel approach? Don't be afraid to state the obvious there - its probably what's needed!

Yes, there is no dropping of the barge board (although what you can see there is "rafter"). The "verge" - thats the concrete between tile and rafter running the edge of the roof I presume?

There are some other similar features. Four of them in fact. Although the others are higher up and probably less exposed than this one.

Matthew, I'm not sure what that plate is. I am as sure as I can be without causing destruction that the wall plate is a single piece and there's no joint behind there. Should that alleviate concerns I might have otherwise?

I have been entertaining the idea of having the first course or two of tiles removed along that face of the building so that new felt could be overlayed to make sure rain water coming off the roof goes into the gutter, and not onto the soffit area. In another location there is very little tile hanging into the air and I think that has caused water to find its way back on top of the soffit and rot it (the old felt previously doing the job having disintegrated now). I presume, Ivor, that if I were to do that, it would make sense to have it done in conjunction with the wall plate splice as similar tiles would need to come off, and a similar repair to the verge would be needed afterward?

Thanks
Steve

MatthewC
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Re: Rotten wood in roof crowsfoot

Post by MatthewC » Tue 15th Jun, 2021 2:32 pm

1895BrickConversion wrote:
Mon 14th Jun, 2021 5:21 pm
Matthew, I'm not sure what that plate is. I am as sure as I can be without causing destruction that the wall plate is a single piece and there's no joint behind there. Should that alleviate concerns I might have otherwise?
Well, it means you are probably OK, but I always ask myself WHY someone has done something!

88v8
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Re: Rotten wood in roof crowsfoot

Post by 88v8 » Sun 20th Jun, 2021 10:41 am

1895BrickConversion wrote:
Mon 14th Jun, 2021 5:21 pm
Speaking of which, Ivor, the job you describe doesn't sound too bad. Would I need a roofer specialising / experienced in older buildings, or would any competent roofer be able to do this. I suspect the latter? And how long would it take - it is on the lower floor of the building - I can reach up and touch it easily, so no scaff required. Is it a day or two of a job for a competent person, or do I underestimate it?
Strip the eaves and verge tiles, carefully not breaking them... you will need spares as I mentioned, and you will need to supply them yourself... support the rafters, cut out the wall plate, scarf in a new piece ready primed, rebuild and repoint the verge. I reckon a full week.

I don't think roofers usually get involved in fiddly external woodwork, you'll need to pick your man. An 'old building' roofer is a better bet. Sorry, I'm far from Essex nowadays, lived in Rush Green long ago.
1895BrickConversion wrote:
Mon 14th Jun, 2021 5:21 pm
And Ivor, when jointing the wall plate, is that "one brick in" one brick lengthwise presumably? What would a traditional splice take the form of - if not Feltwell's butt-up and super dowel approach? Don't be afraid to state the obvious there - its probably what's needed!
Yes, about 9".
A scarf joint of some form, at its simplest this, screwed (stainless) and glued. To counteract the leverage of the verge rafter it should be scarfed under the existing wallplate
https://duckduckgo.com/?t=ffab&q=scarf+ ... fJoint.png
1895BrickConversion wrote:
Mon 14th Jun, 2021 5:21 pm
The "verge" - that's the concrete between tile and rafter running the edge of the roof I presume?
There are some other similar features. Four of them in fact. Although the others are higher up and probably less exposed than this one.
Yes. And if the verge pointing is sound, some of the verge tiles will be broken when the lower part of the verge is dismantled, which is why you will need matching spares, especially tile-and-a-halfs.
Higher features, out of reach out of sight more in the weather.... I would expect on the whole to be worse. Do take a careful look.
1895BrickConversion wrote:
Mon 14th Jun, 2021 5:21 pm
I have been entertaining the idea of having the first course or two of tiles removed along that face of the building so that new felt could be overlayed to make sure rain water coming off the roof goes into the gutter, and not onto the soffit area. In another location there is very little tile hanging into the air and I think that has caused water to find its way back on top of the soffit and rot it (the old felt previously doing the job having disintegrated now). I presume, Ivor, that if I were to do that, it would make sense to have it done in conjunction with the wall plate splice as similar tiles would need to come off, and a similar repair to the verge would be needed afterward?
Yes. Assuming there ever was felt. Our previous house - 1920 - was never felted. Nowadays one uses edge trays/eaves trays at the eaves if possible, more durable.https://www.ebay.co.uk/b/Eaves-Tray/259 ... olid=10001

Ivor

1895BrickConversion
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Re: Rotten wood in roof crowsfoot

Post by 1895BrickConversion » Sat 24th Jul, 2021 3:55 pm

Ivor

Slow to reply to this I know. I thought I would post when I had a clear direction, but things seem to take their time to get correct.

I wanted to say thank you for your advice in the meantime.

Steve

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