Flat roof.

[Dave Plowman (News)]

I have a partial flat roof to the rear of this Victorian semi's main roof. The idea being to make a larger attic room - there is a large full height window on the rear wall so it was the only way to do it without increasing the overall height.

It was properly constructed with marine ply boarding and in a sort of (gentle) V shape with a lie to the rear for drainage, all designed by a decent architect. No pools of water collect even in heavy rain. Normal good quality roofing felt was used, with lead flashing all round.

However, it's now 25 years old and started leaking.

I see all these magic rubber or plastic products on Grand Designs etc, and wonder if any are suitable for DIY? Not sure I fancy doing the normal 'torched' on felt, as it would be new to me. Access is fairly easy via a roof terrace on the rear addition.

Another 25 years will more than see me out, so I'm not willing to spend some ridiculous sum on it. But roofers round here tend to want the sort of hourly rate a solicitor would be proud of, so I'm happy to spend a bit more on materials if DIYing.

[Peter Parry]

I've done three roofs over the years with fibreglass, the oldest (and first) is now 30 years old and still fine, it has never needed repair. Fibreglass is a straightforward material to work with and gives a surface which resists light, is strong enough to walk on and doesn't degrade with time.

[Andy Burns]

I had weetabix and traditional felt roofs on my garage, kitchen and porch.

Re-boarded using marine ply then used a roll of EPDM, the place I got it from has ceased trading so can't recommend those, but there are other around. You need different adhesives for glueing it to the roof and the upstands to the wall. definitely a two-man job to install unless it's a tiny area.

In 7 years the worst that has happened to it is a bit of lichen growing, no signs of going brittle or anything ... of course you have to wear nice flat soled shoes if ever you walk on the roof, rather than your hob-nailed boots!

[Dave Plowman (News)]

What would it cost for approx 6x5 metres?

[Andrew Mawson]

Did you actually use marine ply, which is HUGELY expensive, or did you use exterior ply or maybe wpb ply. Genuine marine ply rarely gets used in building construction.

AWEM

[Peter Parry]

Looking at a number of online calculators about £300-400 ex VAT.

30 sq/m would need about 45kg of resin and 15kg of topcoat.

seems to be quite a good guide, there are plenty of on-line suppliers. The (mail order) one used 30 years ago was Glasplies

[Dave Plowman (News)]

Was hoping their might be something more DIY friendly than fibreglass. Something more like felt - but without needing a blowtorch.

[Andy Burns]

Did my EPDM post not make it through?

[mike]

I used Easy Seal from Wickes for a flat-roofed extension at our last house. It's self-adhesive and was pretty simple to apply. Don't know about longevity as we moved shortly after but it has a fair number of good reviews on their website.

I was considering fibreglass for our current extension but am tempted to go with the Easy Seal again as I suspect it would be easier to balls up the fibreglass on a first attempt.

[Andy Burns]

You're right it was WBP.

[Tim Watts]

On Sunday 15 September 2013 18:58 Dave Plowman (News) wrote in uk.d-i-y:

That sounds like rubber then.

[Peter Parry]

Having helped with a variety of roof coverings over the years I have always found fibreglass was always the most DIY friendly. The materials are easy to work with, it requires no great amount of practice and faults afterwards are easy to rectify reliably. You do need a couple of dry warm days though.

Felt was always a disaster involving burning all clothing and footwear afterwards (and usually the building) only to find it leaked a month later. Rubber sheets of various sorts leaked at folds and joints and were easily damaged by walking on them. The only successful rubber coated roof I came across was done by an architect and involved an inverted roof, where the roof was coated with gravel to a depth of 6in on top of the rubber sheet. This spread the load of walking and provided excellent solar protection.

[george - dicegeorge]

we used permaroof EDPM to replace aleadvalley, i might go on their course...

[g]

[Arthur32]

Actually these flat roofs are more attractive and good as compare to other. These kind of things should keep in mind when you are planning to construct your house.

'pest control services Brisbane'

[Dave Plowman (News)]

Still a bit undecided.

Can someone give me a ball park figure for pro re-felting - it's about

5.5 x 4 metres. Lead flashing etc look fine. Am in SW London. To help me decide if I have to DIY. It's a bit out of my comfort zone.

[Tim Watts]

On Tuesday 17 September 2013 12:54 Dave Plowman (News) wrote in uk.d-i-y:

Last year, my dormers were £1800+VAT to do 2 flats, each 2.5x4m

Good quality mineral felt laid with molten tar + torch.

That included 50mm celotex between rafters, new uPVC fascias and new OSB deck.

To balance that, they were already up there doing the rest of the roof *this was an incremental job) so the scaffolding etc was already there.

[Merryterry]

Why not look at liquid applied PU or Acrylic. There are lots on the market. Applied by roller. Lots of the NEC Roofs are coated with PU. I successfull y sold them some years ago and many were DIY Jobs. Dont use Black as it abs orbs UV. Most of them can have Random Fibre Fibreglass Mat incorporated and can be moulded into upstands etc. Look at Liquid Plastics Decothane and ot hers.

Merryterry

[Bill Wright]

As a matter of interest ordinary solicitors don't get paid much, even though the practice charges their time out at a high rate.

Bill

[robgraham]

On Tuesday, September 17, 2013 12:54:26 PM UTC+1, Dave Plowman (News) wrote :

I'm near Edinburgh and have a roof of a similar age and size which has not started to leak thank goodness. It's pebble covered.

My roofer is quoting £400 to top coat, which should see me out, and £80

0 to strip and re-felt.

Rob

[The Other Mike]

That applies in many professions. 30 to 50 times is not unusual