DIDO.1 20,865 Posted July 13, 2019 Report Share Posted July 13, 2019 I have a flat root on a kitchen extension. It's felted. Hopefully I'm either going to build up and put an another room above it, if I don't get round to that then I at least want to put a pitch on it. But for now I'm worried that it holds water. There is no damp inside but its a concern. What shall I do with it? Shall I paint it with roof tar? Just paint the joints or all of it? Shall I do a few coats where it holds water to try and build it up? Quote Link to post Share on other sites
gnipper 5,948 Posted July 13, 2019 Report Share Posted July 13, 2019 Why don't they put a decent fall on flat roofs so that water can't collect like that? Quote Link to post Share on other sites
DIDO.1 20,865 Posted July 13, 2019 Author Report Share Posted July 13, 2019 4 minutes ago, gnipper said: Why don't they put a decent fall on flat roofs so that water can't collect like that? Not a clue mate. Iv got that roof and a flat roof on workshop and I'm constantly looking at the ceiling for damp. Surely one piece of 2x3 along one wall plate would shake a bit of water off 1 Quote Link to post Share on other sites
dublin dezzy 1,023 Posted July 13, 2019 Report Share Posted July 13, 2019 if you had the money I'd strip it back at least 4 tiles creating a bellcast on roof. Can see where the ply under the felt is sagging,them flat roofs are a nighmare if not done right 1 Quote Link to post Share on other sites
Greyman 25,259 Posted July 13, 2019 Report Share Posted July 13, 2019 5 hours ago, DIDO.1 said: Not a clue mate. Iv got that roof and a flat roof on workshop and I'm constantly looking at the ceiling for damp. Surely one piece of 2x3 along one wall plate would shake a bit of water off Get them fibreglassed will still have sitting water on but will remain watertight for long after you stopped worrying about it , 5 Quote Link to post Share on other sites
The one 8,397 Posted July 13, 2019 Report Share Posted July 13, 2019 Half the houses in the street have roofs like that as there bedrooms go into the roof annex and every 7 to 10 years they get them refelted and you see the odd one getting stripped right back and new chipboard sheets put in across the rafters refelted then tarred , There feck all but bother as said if you can i would put a sloping roof on it Quote Link to post Share on other sites
slip lead 862 Posted July 13, 2019 Report Share Posted July 13, 2019 (edited) The ferring pieces are to small, strip back to joists, most builders buy 4x2 and make 2, 2" ferring pieces, some times over a large exspance, this is not enough of a fall close to the fulling edge. Also make shore, you start laying full boards, from bottom of full, then your cuts will be at the top and won't flatten out. Edited July 13, 2019 by slip lead 1 Quote Link to post Share on other sites
DIDO.1 20,865 Posted July 13, 2019 Author Report Share Posted July 13, 2019 I don't want to feck about with it this year, shall I tar it? Add chips? Quote Link to post Share on other sites
dogmandont 9,341 Posted July 13, 2019 Report Share Posted July 13, 2019 7 minutes ago, DIDO.1 said: I don't want to feck about with it this year, shall I tar it? Add chips? I’d just paint the whole thing with a decent sealer until you’re ready to sort it proper. Quote Link to post Share on other sites
trigger2 3,100 Posted July 13, 2019 Report Share Posted July 13, 2019 I think you can by rubber roofing at a reasonable price if you shop around, if that’s laid properly you won’t have any problems. 1 Quote Link to post Share on other sites
shovel leaner 7,648 Posted July 13, 2019 Report Share Posted July 13, 2019 Greyman, is spot on , fibreglass is the way to go . Get it done and forget about it . 1 Quote Link to post Share on other sites
NEWKID 26,191 Posted July 13, 2019 Report Share Posted July 13, 2019 6 hours ago, Greyman said: Get them fibreglassed will still have sitting water on but will remain watertight for long after you stopped worrying about it , Better still use a single ply membrane, designed to have sitting water, can be laid perfectly flat... you can adhere straight to the felt with a fleece back membrane, most are 20 year guarantee...we use Renolit, Alkorplan...you need to be an approved installer to supply....watch out for off the shelf cowboys, like Rephanol... materials crap and sold to anyone... If you do go down this route, Sarnafil, Trocal or Alkorplan are all good systems with trained installers only... Quote Link to post Share on other sites
Nicepix 5,650 Posted July 13, 2019 Report Share Posted July 13, 2019 8 minutes ago, shovel leaner said: Greyman, is spot on , fibreglass is the way to go . Get it done and forget about it . Yep! Buy some 450g / m2 fibreglass (about 6 times the area of roof so you can overlap and put at least two layers on) and some resin. It is dead easy to do and as long as you overlap the edges it will be waterproof for years. 3 Quote Link to post Share on other sites
NEWKID 26,191 Posted July 13, 2019 Report Share Posted July 13, 2019 31 minutes ago, timmytree said: My last loft extension I did myself, fitted firring strips of 3 inches down to nothing over 4.5 metres. Marine ply deck on 6 x 2 timbers, 3 layers of felt with big overlap joints staggered on each layer. Full bitumastic layer between each felt layer. After 10 years it was still fine but topped it with another bitumastic layer and top felt. Sold it 6 years ago and its still fine. Put a decent fall on a flat roof and it will last a lot longer. Proper felting, 3 layer pour and roll.... my Grandad and my dad would be proud...Dads 68 now and still does the odd roof, my grandad felted until he was 73 (dead now).... my old man says we've ruined his trade with these new fangled products...I tell him to give up ffs.... lol 1 1 Quote Link to post Share on other sites
NEWKID 26,191 Posted July 13, 2019 Report Share Posted July 13, 2019 3 minutes ago, Nicepix said: Yep! Buy some 450g / m2 fibreglass (about 6 times the area of roof so you can overlap and put at least two layers on) and some resin. It is dead easy to do and as long as you overlap the edges it will be waterproof for years. I'm not a fan of the finish on big areas, great for penetrations, awkward spots etc....just think it looks a bit ugly as a main field area....just my opinion though, and certainly us effective... Quote Link to post Share on other sites
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