We’re looking at getting an modest extension on the back of our house to replace a ramshackle lean-to affair we already have. Our builder is recommending a flat roof saying it will be cheaper and as a main benefit it will improve access to the main roof of the house which is currently hard to reach.

Also having a pitched roof slate roof (of the correct pitch) would be imposing to our neigbours.

So are flat roofs still to be avoided or are modern construction methods way better than the 60’s/70’s?

why not, the continent is covered in them, as long as they are built properly i dont see why there would be a problem? i guess it can be very easy to make a mess of it.
as long as there is a Slight pitch to it, so water cant stand on it, you cant go wrong?

refelting a roof isnt hard, when the felt fails in however many years (o preferably before it fails) or do what they did on grand designs, and build a roof that is designed to contain a few inches of water under a gravel bed, which keeps the sun and heat off the felt, so it lasts alot longer (your roof has to be able to hold the weight of the gravel + water though)

Go for a sarna system. Great stuff, welds up on joints corners etc perfectly!! It’s a great system!

Pitched all the way. If it’s a modest extension a modest (i.e. low)pitch won’t affect your neighbours too much. My Dad was a flat roofer who guaranteed work for 10years, don’t think he ever went back to one (in 30+ yrs of doing the job). Think horror stories are down to workmanship. The re-sale of a pitched roof is always better especially if you vault the ceiling and stick in a velux. Your modest extension will seem a lot bigger for minimal cost. So for reasons other than reliability I’d go pitched……tiling is also a LOT easier than felting, if you’re thinking of repairs in 25yrs. (my original slate roof was re-done after over 100yrs only because the nails rusted and slates slipped!).

Go for a Permaquik or Sarna warm deck system. Get it electronically tested. Will be fine for 25 years plus.

I’ve done two rubber ones in the last year, they seem really good. I went with firestone.

Also done a couple of small grp ones, they’re really solid. Great for over bay windows and porches, never seen a large area done though

Ex roofer and i say Pitched.

Ex roofer and I say lead 🙂

An example of some work I have done, not flat but lead is very versatile!

http://www.shireroofing.co.uk/index.html

But if it has to be flat then sarna is the kiddy!! Used it on a balcony that basically sat over the fining room of a development and we’ve been using sarna gutters on industrial for years now!!

I’d prefer zinc, copper or titanium – but Sarna (or Trocal) will last for years. I’ve specified about 40,000sqm of it without a problem.

Ref the Sarnafil roofs beware that in some parts finding a Sarna approved contractor can be difficult (only 4 in Scotland). And to get the guarantee it needs to be an approved contractor and the work checked by one of Sarna’s field techs on completion.

But agree with the sentiments – single ply membrane all the way, others such as Bauder (German system) or Protan (Swedish) are also very good.

Is that right neallyman??? We had an approved contractor do the balcony but it never been inspected! As for the sarna gutters we use on commercial I’ve never had any inspected on projects worth millions???

I’ll be looking at replacing the flat roof on kitchen extension. I’ve followed the Sarna documentation and looks like a good option. How much does it roughly work out for a small extension of around 20 Sq mtr?

Yeah wrightyson, was advised this by Sarnafil themselves just this week, how rigidly they police it and see it through however I couldn’t say. But I’d personally want the piece of mind should I ever need to envoke the warranty…

Ive managed several projects using Bauder systems and they are pretty good. The manufacturers inspection of the completed job (when using an approved installer) is essential in getting the guarantee validated as mentioned above.

We got a couple of mortgages refused on a property with a flat roof.

It might affect your re-sale if that matters

I would never buy a house with a flat roof; for me it’s as bad a concern as subsidence or blocked drains.

I would never buy a house with a flat roof; for me it’s as bad a concern as subsidence or blocked drains

Didn’t realise flat roofs would cause such strong reservations in this way but genuinely find this sort of viewpoint interesting…

Can’t comment from the building side but living in a block of flats with a flat roof I can confirm it’s a PITA for mortgages (certain companies won’t entertain it meaning the ones that do can charge more), might not be as bad with a house, and it’s a PITA with insurance companies. Sick of having the conversation ‘what kind of roof is it?’ ‘flat but it’s about 5 floors above me’ ‘sorry, we can’t insure you’ ‘ grrrrrr’.

I would never buy a house with a flat roof; for me it’s as bad a concern as subsidence or blocked drains
Didn’t realise flat roofs would cause such strong reservations in this way but genuinely find this sort of viewpoint interesting..

I wouldn’t buy a house with a flat roof either – extension I had I went for a pitched roof.

If you can happily mix roof coverings and avoid slate there are are tiles which go down to 15 degrees or even 12.5 degrees. (eg Marley Malverns).

I recently replaced a crappy freezing cold flat felt 1970’s roof with a 15 degree pitch tile, and I also managed to significantly exceed building regs with the new insulation. – What a massive improvement.

A well constructed flat roof is better than a poorly constructed pitched roof; it’s down to the quality of construction.

I’d have a well constructed flat roof with french windows from bedroom above onto a balcony 8)