We have a GRP Topseal flat roof. It is a flat roof within a parapet wall - so meets brick on asll 4 sides..As far as I can tell it looks to me like the mat and bonding have just been ran up the wall...(there are water stains in the corner of the ceiling) I assume there should have been a C and D trim all round - or something? In which case can I just add the trim and reseal or do does it need to have been integrated with the original bond to be successful..
Adding trim to a GRP flat roof
- Thread starter walter111
- Start date
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If it was a company installed it and there's a warranty then (as other post) get the company back in. If it's DIY then the materials will be guaranteed for 25 years but only if they've been used properly.
Does the GRP go all the way up the parapet walls or does it stop a few inches above the deck? If the latter then yes there should be trims between the deck and the wall (10mm gap between the deck and the wall recommended) and then a cover flashing chased into the wall and covering the vertical bit of the trim to just above deck height.
You can put the trims on now but you'll need to grind/sand the topcoat off and get a decent key into the laminate. Fix the trims (nails and PU adhesive). Wipe your sanded area down with acetone (give a better key for resin). Resin and bandage (or use 100mm bits of mat if you want) the trims to the main deck- you want at least 50mm overlap to the deck and 50mm onto the flat bit of the trim.
Once the resin has cured, topcoat the sanded bits then put your cover flashings on (can be fibreglass, lead, Ubiflex, whatever)
If the GRP goes all the way up to the top of the parapet then there should still have been a C section trim between deck edge and parapet and the parapet wall should have been boarded or clad with flat sheet. If that has been done (so you've effectively got a tank) then make sure there's some sort of coping on the top of the parapet walls (could be GRP, could be anything as long as there's a seal and water can't get down behind the GRP)
You need completely dry weather for playing with resin and ideally some sunlight (the UV helps cure the stuff) so this time of year isn't ideal.
Does the GRP go all the way up the parapet walls or does it stop a few inches above the deck? If the latter then yes there should be trims between the deck and the wall (10mm gap between the deck and the wall recommended) and then a cover flashing chased into the wall and covering the vertical bit of the trim to just above deck height.
You can put the trims on now but you'll need to grind/sand the topcoat off and get a decent key into the laminate. Fix the trims (nails and PU adhesive). Wipe your sanded area down with acetone (give a better key for resin). Resin and bandage (or use 100mm bits of mat if you want) the trims to the main deck- you want at least 50mm overlap to the deck and 50mm onto the flat bit of the trim.
Once the resin has cured, topcoat the sanded bits then put your cover flashings on (can be fibreglass, lead, Ubiflex, whatever)
If the GRP goes all the way up to the top of the parapet then there should still have been a C section trim between deck edge and parapet and the parapet wall should have been boarded or clad with flat sheet. If that has been done (so you've effectively got a tank) then make sure there's some sort of coping on the top of the parapet walls (could be GRP, could be anything as long as there's a seal and water can't get down behind the GRP)
You need completely dry weather for playing with resin and ideally some sunlight (the UV helps cure the stuff) so this time of year isn't ideal.
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