Check out the price of a kit from Permaroof if you do it yourself, its not difficult. And because it comes in a single sheet you dont have to do it all in one da y, you can drape the sheet over before gluing if it rains, and stick one edge on day, the rest another day.
It took me months to do parts of my house roof with it because so many corn ers
[g] [g]
True enough, though glassfibre has been about for quite a number of decades in other things like boats.
Possibly by taking the ceiling below out, but then I'm not sure that making good the ceiling is going to be much less work than redoing the roof. (There may be asbestos fibres in the ceiling, just for added excitement)
Theo
Just had our garage completely re-roofed. Cost about 900 GBP. That ws after more than 25 years use and the old roof was very badly installed, according to the roofer who stripped it off, whixh id why it blew off.
I reckon if you've had 20 years out of it that's not bad and maybe it's time for a completely new one.
- Mike
Interesting. This is also a garage (conversion), let me guess about 6m x
3.5m. That sounds rather cheap!(2-3K quotes did not include removing much woodwork assuming it to be otherwise sound)
That was the initial assumption. However it doesn't seem to have failed completely, so wondering if there was something that could keep it going for a bit longer (pending other things).
Theo
Joints in flat roofs are almost guaranteed to fail, especially if both were originally built-up 3 -layer felt and one half has been replaced with 2-layer torch-on felt. The heat of the sun, and the dryness, especially the weather we have had this year will soon make the joint fail.
IS the decking chipboard, plywood or OSB ? The first will not like ingress of water.
If you are going to treat flat areas their special primer is well worth using first.
I did my garage roof with an EPDM kit, but that involved redecking with OSB3 first. 5.5 mtres by 2.8 metres. It was just on the limit of my ability to get it up the ladder. A 5x5 sheet of epdm will need
2 people.Flat roofs need replacing at least every 20-25 years. Some really bad bodge jobs, like the garage roof of my first house was done in
2-layer felt in 1976, before the days of fibreglass reinforced felt and every house had a leaking garage roof within 10 years.
Isoflex, when used with its special primer should add about 8 years to the life, provided it has no ponding or other problems.
The 1.5 mm stuff is pretty tough. If it never or rarely gets walked on then you would have to be very unlucky to damage it, unless you have an arsewipe as a neighbour who chucks hydraulic oil and or solvents on it.
It is glued onto OSB3/plywood using a water-based adhesive that is rolled on with a decorating roller so as well as the EPDM itself you have this layer of adhesive that seeps into the decking and provides a 2nd level of protection.
You said it had already been treated with something, so the actual original probably lasted 20-25? years which is about right for a built-up felted roof. Unless you want to reseal it with Isoflex or whatever every 5 to 8 years thenyou might as well just get it re-felted.
Avoid Acrypol if you have already using Isoflex, the two are not compatible. DTDIGTTS.
Sounds like it has already leaked allowing the decking to weaken and sag, hence the ponding. Complete re-decking it the solution.
Be aware that part L means it will need to be insulated and too many roofing people will insist on adding insulation on top of the decking and then putting the felt over the insulation. If your flat roof is a 'cold roof' (most are) , this is s complete waste of time since the ventilaton will still allow cold air to circulate underneath the insulation.
If the roof is redecked then adding 'celotex' between the joists and cut to fit snugly, and the joints taped with silver foil tape with an air gap above it is the way to go.
For redecking and felting, the going rate seems to be about £100 per square metre.
I did my garage roof myself, 5.5 metres by 2.6 metres and is cost me £700 just for materials, -
6 sheets OSB3 @ £21/sheet 4 new rafters to replace rotten ones UPVC cladding over existing barge boards EPDM kit, with adhesive, guttering and upstand trims Screws and fixings. OSB3 must be screwed not nailed.
That's what I suspected. Although I wondered if there was a say 5 year shorter term fix?
This is a semi-integral garage, so I'm not sure part L applies? It's still got a great big garage door, even if the internals are a bit nicer than a normal garage. It isn't heated.
Quoters seemed to suggest stripping it back to add insulation would be much more than a simple re-roof.
Trying to avoid 'and while you're doing that...' project creep.
Theo
No, but the internal garage walls are partition walls separating garage from living rooms/kitchen, so hopefully they will be insulated. If its a 1960's build then insulation will be minimum.
Back in '13 or 14 we had a very bad felted roof & looked primarily at EPDM & steel. In the end a temporary job was done using bedsheets, bitumen & san d without stripping any of the damaged felt. Last time I checked it was sti ll fine. Given that I'd take that approach again in future. Total cost was under £25 & it was quick compared to a new roof. Just wear junk cloth es, they will get ruined.
Early flat roofs were deliberately ponded to increase felt life expectancy. It was soon learnt it wasn't the best idea, but it's not a game ender eith er. If you cover a sagging roof you take a gamble on its life expectancy, b ut it's £25 versus far more.
NT
Interesting, thanks. In this case it's at the front of the house so a bit wary of conspicuous bodging... (and DIY isn't an option in this case)
I came across:
which was 1.3-1.4K for a 3.5x6m flat roof with timber (optionally insulation) in London/SE. Does that sound more plausible than the 2-3K already quoted?
Theo
Flat roofs in Germany are ?always made to force ponding for some reason. On a Grand Designs program, from many years ago, a house in East London was given an expensive makeover with a big extension that specified a German flat roofing system, and people came over from Germany to do the roof. It leaked !
It looks the same as any felt roof. The finish used was sand, you can also get stone waste for a nicer look. That would up the cost to near £30 t hough :)
NT
Marine ply won't disintegrate if it gets wet - it'll just dry again.
Unless it keeps getting wet, when it will rot just like any other wood.
Andy
Marine ply is one of those things much talked about but never seen in diy or pro house maintenance. If someone says marine ply, it's something else.
NT
Most timber yards round here sell it. Or rather what they call marine ply. At about 5 times the price of general purpose stuff.
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