Flat roof - again.

[Dave Plowman (News]

Heavy rain all yesterday shows my flat roof is leaking again. It's felt, and about 30 years old. Been 'fixed' a few times, but time to replace.

The deck is good quality ply, so hoping that is still fine. All the flashings etc lead. It was designed by a decent architect, and installed by his recommended builders and roofers.

Size is approx 3.5 x 4 metre

Anyone give a rough guide as to costs - felt, membrane, glass fibre?

Access is easy so no scaffolding needed.

At my age, even felt done well is likely to see me out. But I'd consider something better - if I can afford it.

[Davidm]

At the beginning of 2020 I had mine redone. About the same size as yours, but decking was chipboard and totally fu**ed. Also 3 stories up so a couple of £100 worth of scaffolding needed. New roof, multi layer felt, hot tar on OSB3 boarding, cost about £2400.

[Dave Plowman (News]

Thanks, David. I was hoping about 3k would cover it.

[tim...]

a false economy

a replacement deck is a trivial part of the whole

it doesn't matter how easy access is, it's how easy it is to fall off that the issue

and that will be much the same for all non-enclosed roofs.

[Chris Bacon]

I have been thinkig about flat rooves. I'd go one piece EPDM. Call up a few people and ask about a price for the job.

[Theo]

Interesting:

About £150 for a single-garage sized piece, plus sundries. If the decking is in good order doesn't look infeasible as a DIY job.

up all the extras.

Theo

[Tim Lamb]

In message [e-mail]>, "Dave Plowman (News)" [e-mail]> writes

Have a look at *Composite Roof Supplies*. I did a 3m x 2.5m porch roof for not very much. Strangely, although I have the delivery note, I can find no record of payment!

There are *how to* instructions here:-

[Dave Plowman (News]

Really?

When did you last buy decent quality ply?

If I feel safe up there, I'd expect a skilled roofer to do too. It has parapet walls.

[Mark]

did you not have that done with Promenade tiles a few years ago?

[Dave Plowman (News]

That is the roof terrace. This is a different flat roof that there's no immediate access to.

[Andrew]

Quite easy to DIY, but whoever does it will have to overboard the existing plywood decking with another layer of ply or OSB3 because the water-based adhesive needs a clean substrate.

[Dave Plowman (News]

Chap finally came round today. He's the builder the architect who designed the conversion all those years ago now uses. I simply don't know any roofers. And would rather go by a recommendation.

Interesting chap. Said he is a builder, not roofer. Who now does roofs on his jobs himself. After getting ripped off once too often with contractors. ;-)

And only does glass fibre. Felt is for sheds, he says. Fairy nuff - no point in learning more than one skill if you're not going to use it.

Tim guessed right. He wants it scaffolded for safety reasons - even although he went up to have a good look without. However, I could make use of the scaffold to paint the window. It was done a couple of years ago. But be silly to pay for scaffolding again in a year or so.

He reckoned about 5 days work, assuming the base is OK. The BOM from the architect specified marine ply, so I'm hoping that's what was used, and is still OK. There are no signs of sagging.

Found an online calculator which reckoned on about 500 quid for materials. He's going to give me a price next week.

[Fredxx]

This might be of interest.

It seems OSB grade 3 might be best. Make sure it is the right grade. Be wary of where he gets the marine ply from. Some is certified, and some isn't.

It is still recommended to paint all edges with a sealer, for both OSB and marine ply.

[Dave Plowman (News]

I'm hoping it won't need replacing. The construction of the roof - and the rest of the conversion was done by Trevor the chippy who I loved watch work - a true craftsman. But didn't say much. This about 30 years ago. He sadly died young. A local roofing firm did the felt and lead work. But they no longer exist.

I didn't see all of the construction stages due to being at work.

[tony sayer]

In article [e-mail]>, Dave Plowman (News) [e-mail]> scribeth thus

E.D.P.M Dave, excellent stuff, we did our garage/workshop for £800 inc the use of a labourer mate for a day essentially its a DIY operation and we were quoted around £4000 bloody thousand quid by three supposed roofers and one wanted Cash and VAT on top of the cash!! Was told to f*ck off in no uncertain terms!

So DIY and it doesn't leak and looks fine this lot supplied and were very helpful all along:)..

[tony sayer]

Theres a few useful Vids on Youtube on how to do it!...

[Dave Plowman (News]

Not going to DIY it Tony. Getting too old to climb ladders, and the hands are getting rather arthritic too.

And rather than risk finding a roofer by picking one with a pin, I'll use the one I've had recommended. So will do what he recommends. Although I've not yet seen his estimate. The general view is fibreglass is the best though. My architect does a lot of extensions etc round here, and is as good as any at not making them stand out like a store thumb - as much as possible. And he now reckons on fibreglass too. Unlike 30 odd years ago when he did this job, when it was felt.

[Dave Plowman (News]

Must admit to wondering why the existing can't be cleaned, if in good condition?

[Chris Bacon]

"You must ensure that the decking is completely dry and clear of any surface debris before applying the ClassicBond EPDM Deck Adhesive. Of course, installation couldn?t be easier making this product ideally suited for both amateurs and professionals alike".

Yoiu can also get a primer for the job.

[Andy Burns]

But if it's been felted before, it'll have asphalt on the deck, which "nothing" sticks to, and it's difficult to get it off completely.