Getting a new slate roof in the North?

BornTooHula

Hi there,

I've been told the property I'm purchasing is likely to need a new roof pretty soon. It's currently original Welsh slate from the late 1800s, but the slate is crumbling from behind and there are quite a few gaps in the tiles showing light coming through. For example this image below:



According to this website, a new roof on a 4 bedroom detached property (which this property is) should cost between £7,000–£12,000, based on a roof size of 100m². Measuring the property using this tool, I get a rough footprint of 85m², but this is just a flat measurement.

Can someone who's had a similar job done advise what the total overall cost is likely to be? I'll also need a insulation and a breathable membrane putting in, and the lathes replacing as they're a bit rotten. I've been advised the purlins and joists are OK. If it comes to choosing slate, I'd be happy with the cheaper Spanish slate I think.

The one person I've spoken to gave me a ballpark figure of £30,000, but this seems a way off from the £7-12k I found online.

Thanks for any help or advice!

FreeBear

BornTooHula said: If it comes to choosing slate, I'd be happy with the cheaper Spanish slate I think.

You might want to rethink Spanish slate. From what I hear, it really doesn't last - https://www.periodproperty.co.uk/forum/viewtopic.php?f=1&t=17373#p233435 - By all counts, 4 years before they start to degrade.

neilmcl

What do you mean "crumbling from behind"? What you're likely seeing is the original lime mortar that's been used to keep the slate's in place, known as 'Torching'. The slates themselves should still be in good condition and it's not unusual to see daylight between them, the way they're laid still prevents water ingress even though you can still see chinks of light coming through. What does that 'Danger' sign say?

stuart45

The problem with Spanish slate is that there's a lot of quarries and quality varies a lot depending on which one it came from.
Canadian slate is decent alternative.

BornTooHula

Thanks for all the replies. 

What do you mean "crumbling from behind"? What you're likely seeing is the original lime mortar that's been used to keep the slate's in place, known as 'Torching'. The slates themselves should still be in good condition and it's not unusual to see daylight between them, the way they're laid still prevents water ingress even though you can still see chinks of light coming through. What does that 'Danger' sign say?

I have read this (in the Haynes manual for Victorian & Edwardian homes) but the Level 3 survey I had on the house, and the builder I took round, said it needed a new roof. I'm pretty new to all this, hence why I'm looking for second opinions in a few different places.

Is there a good way to tell whether the roof needs replacing or repairing?

I'll look into Canadian slate - thanks!

rob7475

Where in the north are you? I can recommend a couple of good honest roofers depending on where you are. They won't tell you it needs replacing if it's repairable.

I assume that if the mortgage survey  has picked this up, the valuation has been adjusted accordingly? That should give you a very rough estimate of the repair cost.

The danger notice was probably put there by the firm tha installed the loft insulation. I think it's just a standard notice they put up to warn of restricted head height or something (can't quite remember what ours says).

BornTooHula

rob7475 said:

Where in the north are you? I can recommend a couple of good honest roofers depending on where you are. They won't tell you it needs replacing if it's repairable.

I assume that if the mortgage survey  has picked this up, the valuation has been adjusted accordingly? That should give you a very rough estimate of the repair cost.

The danger notice was probably put there by the firm tha installed the loft insulation. I think it's just a standard notice they put up to warn of restricted head height or something (can't quite remember what ours says).

The house is in Sheffield, so would appreciate any recommendations for trustworthy roofers in the area. 

The mortgage valuation didn't mention the roof (they did mention some other things that needed addressing, including a leaning chimney). I paid for a separate RICS survey (Level 3) and they highlighted the roof needs replacing.

A friend-of-a-friend who is a builder quoted around £30,000 to replace the roof, which seems like a lot. That said, he just had a quick look and said he'd be able to offer a more accurate quote once measuring properly.

Any other thoughts appreciated. Thanks!

stuart45

You are asking how to tell if the roof is shot. With a Welsh slate roof it's often the nails that fail first and you notice some of the slates slipping down the roof. Welsh slates are long lasting, but you do find that after a 100 years or more that some of them will be turning to powder.
Some people will carefully strip the roof and re-use most of the slates.
A lot of roofers won't do this.
Another method is to have a look in the loft when it's hammering down.

neilmcl

BornTooHula said:

Thanks for all the replies. 

What do you mean "crumbling from behind"? What you're likely seeing is the original lime mortar that's been used to keep the slate's in place, known as 'Torching'. The slates themselves should still be in good condition and it's not unusual to see daylight between them, the way they're laid still prevents water ingress even though you can still see chinks of light coming through. What does that 'Danger' sign say?

I have read this (in the Haynes manual for Victorian & Edwardian homes) but the Level 3 survey I had on the house, and the builder I took round, said it needed a new roof. I'm pretty new to all this, hence why I'm looking for second opinions in a few different places.

Is there a good way to tell whether the roof needs replacing or repairing?

I'll look into Canadian slate - thanks!

It's true, given it's age, that the roof is probably coming to the end of it's useful life, but that tends to mean the fixings for the tiles are no longer much use, the slate itself can last indefinitely if looked after and there's no reason why a lot of it could be re-used. It might be worth posting some pics of the outside of the roof to see the condition of the slates. Also, just because you could do with a new roof I wouldn't necessarily say you "need" a new roof straight away, you just have to accept that you may be paying a couple of hundred every year or two to maintain it when the inevitable slate slips due to failing nails.

I wouldn't put too much faith in the quote you got from your general builder, seek some quotes from recommended roofers in your area, check out you local FB pages etc, and be wary of anyone saying they could do it within the next month or so, any decent roofer will be fully booked up, possibly for the rest of the year. Personally, I'd think you should be looking at around £10K, possibly a tad more (or less if you can re-use as much slate as you can or choose a different covering).

BornTooHula

Thanks - this is all really useful information.

I'll reach out to a couple of different roofers and see if I can get comparative quotes. From what I've seen online, it looks as though some Spanish slate is great, but others not so good. Just another thing to watch out for I suppose.

I am worried about getting a roofer who will take off lots of perfectly good Welsh slate from my roof, potentially take it away to resell on the sly, and fit me with an unnecessary complete roof of Spanish slate.

joe90mitch

BornTooHula said:

Thanks - this is all really useful information.

I'll reach out to a couple of different roofers and see if I can get comparative quotes. From what I've seen online, it looks as though some Spanish slate is great, but others not so good. Just another thing to watch out for I suppose.

I am worried about getting a roofer who will take off lots of perfectly good Welsh slate from my roof, potentially take it away to resell on the sly, and fit me with an unnecessary complete roof of Spanish slate.

Please do post how you get on! Though I do have a small vested interest - live in Sheffield and also a have welsh slate roof, so it'd be good to know if you have a good experience in the end for future reference.