Valley repair with liquid GRP

[gravelld]

We've got some holes in our lead valleys and want them fixed.

 

Two roofers have recommended just coating them in liquid GRP. A final roofer said it doesn't last and we should put in a new lead work and valley.

 

Does anyone have any experience of liquid GRP and how long it might last? Trying to weigh up the cost/benefit.

[SteamyTea]

1 hour ago, gravelld said:

Does anyone have any experience of liquid GRP

Having been in the GRP business and had an interest in it for over 50 years, I have never heard of it.

Did then give a product name?

[saveasteading]

I'd first try bitumen paint, encouraging it into the cracks then a couple more coats.

I recall there is  a product with fibres in it which would help clog the holes.

I'm assuming these are cracks or small holes  not  big holes.

[Redbeard]

Lead, done right, will last 100 years. GRP can last well (and ST will have a better idea than I about GRP longevity, but still a lot of old GRP boats around) but I would have thought a lot less than 100 years. Lead gets my vote.

[joe90]

I have replaced several lead valleys with GRP very successfully, I have doubts about patches “sticking” to lead?. Advantages of GRP is no joins as needed in sheets of lead and far cheaper.

[SteamyTea]

2 hours ago, Redbeard said:

and ST will have a better idea than I about GRP longevity

Stuff I have done has lasted more than 45 years so far.

Generally it gets taken down before it fails.

 

I hear good things about this sort of product.

https://www.everbuild.co.uk/products/roofing/roof-repair/aquaseal-liquid-roof/

I have never applied it, but we had the shop roof done with some a couple of years ago and it is still holding up as far as I know.

[gravelld]

I'm not talking about replacing a lead valley with a GRP one - I'm just talking about going over the lead valley with a coat of the GRP.

 

I have also used those flashing patches successfully, and they do stick so long as the lead is cleaned up nicely. But they are even more temporary I think!

 

18 hours ago, saveasteading said:

I'd first try bitumen paint, encouraging it into the cracks then a couple more coats.

I recall there is  a product with fibres in it which would help clog the holes.

I'm assuming these are cracks or small holes  not  big holes.

 

Yeah they are fine fissures/tears in the lead.

 

I think this lead is about 25 years old. One of the roofers commented the runs were too long - they should be cut to maximum 1500mm runs, he does 1200.

[saveasteading]

38 minutes ago, gravelld said:

fine fissures/tears in the lead.

On the other hand, don't mess with valley gutters. So paint it for a quick fix, but get it fixed in better weather.