Extending the life of an ageing slate garage roof

[d000hg]

Our 'garage' is in fact a 19th Century circa 1870 coach-house - complete with a fireplace and chimney!
We don't know if the roof is original but it is certainly very old and in bad shape. It started leaking the other day in a storm and when someone went up to have a look they reported the slates were "paper thin" and almost impossible to get fastened in place, since some battens are also suffering rot, there's nail sickness, etc.

Long term we plan to totally re-do the whole roof but we don't have the funds or time right now.
All I would like is to hold it together water-tight as long as possible to buy some time, at least over the winter, as I store a lot of stuff in there.

Are there any tricks or tips to bodge a failing roof, even ugly ones that might damage it and would only be suitable since we expect to rip the whole thing off later?
Nailing anything is tricky since the slates either break or as soon as you touch one, the neighbours slip.
I'd wondered about using some sort of adhesive or sealant or something just to bind it all in place a bit - is this feasible?

Luckily, wind isn't particularly an issue as it is super sheltered - which caused another problem with it getting VERY mossy, which re removed to find how bad the slates were underneath!

 

[mikeey84]

Spray foam insulation is normally discouraged due to the issues it can cause, but given you are suffering from them already, and it's going to be ripped down, it could be an option.

Might be a bit pricey though for a temporary fix!

 

[charliegolf]

Spray foam insulation is normally discouraged due to the issues it can cause, but given you are suffering from them already, and it's going to be ripped down, it could be an option.

Might be a bit pricey though for a temporary fix!

What about using foam like a weld- just at the joist/slate junction? A squirt on any holes too?

 

[d000hg]

Spray foam insulation is normally discouraged due to the issues it can cause, but given you are suffering from them already, and it's going to be ripped down, it could be an option.

Might be a bit pricey though for a temporary fix!

I've not come across that before but Googling I can see both why it could help, and why it's discouraged!

It does look pricey, I wonder if something similar might be possible that is solely used to 'glob' all the tiles together.
We previously glued one tile in place with waterproof adhesive onto its neighbours but that was just one tile. I hadn't considered spraying something on the inside, but now that does seem the logical answer if I must bodge it.

 

[oldbutnotdead]

Are the leaks up at the ridge or further down?
Depending on access and how big the roof is you could fix tarpaulins over it.
Or use Gripfill to stick patches of tarp over the worst holes
Or use Acrypol or similar liberally daubed on the gaps
Or for a shortish term lashup you could tarp under the rafters and arrange an internal gutter lashup to keep rainwater off your stuff.

 

[d000hg]

Are the leaks up at the ridge or further down?
Depending on access and how big the roof is you could fix tarpaulins over it.
Or use Gripfill to stick patches of tarp over the worst holes
Or use Acrypol or similar liberally daubed on the gaps
Or for a shortish term lashup you could tarp under the rafters and arrange an internal gutter lashup to keep rainwater off your stuff.

Hmm, I guess tarps would work but it's probably one level too far on the "ugly bodge" scale since the building is kind of a feature. If it was definitely just for a month or 2 it sounds a great option, but my fear is it might end up there in 3 years if it works TOO well
In an ideal world we want to renovate the entire building but that would be a couple of years. I don't know if I can eke that out of the roof without visibly ruining it so we might replace it sooner but it actually looks fine from the outside, you just can't work on it without causing more issues

Patches of tarp if we just need to address one bit could work though especially in an emergency.

I'd not come across acrypol but it also sounds interesting for a small area - this is basically painted on a bit like tar, and just seals everything together as it sets?

 

[garyo]

I cringe saying it, but you can get all kinds of bodgy roof repair paints, such as those gloopy acrylic things, so you could coat the whole lot in one of those. With most of these solutions you'll be significantly increasing your levels of waste in a few years, compared to some lovely disintegrated slate that you could sprinkle on top of your favourite flower bed.

 

[cdbe]

Have you considered EPDM? I know it's quite pricey as a temporary measure but maybe not for the short/medium term - you'd just have to devise a way to securely hold it down. When I considered it for my garage roof a few years ago someone was selling seconds (slightly crumpled) on eBay.

 

[scbk]

I would say just keep it as it is for now, repair what leaks are there, if you can't nail the slates back on use a good silicone

 

[bobasd]

on a slate roof - no matter the condition - i wouldn't use any foam or any other "sticky stuff.
you could end up ruining still valuable slates - or at least causing lots of extra work for yourself.
stay away from tarps or patches - they could blow off on to anyone or anything.
neither do you want anyone wandering about on your roof causing more problems than they solve.

what you describe is common enough and hardly ever allows you extra time once it starts going - bite the bullet and do it properly - and cheaper.

 

[d000hg]

Like I said the slates have flaked to the point they're like paper. Sadly I don't think they are salvageable.

Replacing the roof will cost thousands I'd guess, all the woodwork is shot... Anyone care to ballpark cost on a total new pitched roof for a 7x4m garage using slate?

 

[datarebal]

Thickness is not always a sign of a dead slate, some of the very best are thin.

post a picture to get an informed reply

 

[d000hg]

I'm going off the word of someone who went up there to work on it and knows their stuff, and isn't looking to find work to do - so you'll have to take as read they are shot and advise accordingly. If you give an informed reply to incorrect facts, that's on me not you

 

[datarebal]

I'm going off the word of someone who went up there to work on it and knows their stuff,

The obvious answer then is ask them..

 

[d000hg]

did, but they don't seem happy to do deliberately bad work, or at least haven't before. The nature of their job is not to bodge things after all.