JLB joinery   10 #13 Posted December 2, 2009 leave the coal shoot open otherwise you will end up with wrotting floor joists which is costly to repair. the best thing you can do is lath the ceiling down fit kingspan insulation betwen them and board over the top thats the most appropriate solution. Share this post Link to post Share on other sites Share this content via...
retired   10 #14 Posted December 2, 2009 (edited) I think you mean cm instead of mm. You say you already have 100mm of insulation installed. If this is a tight fit then it should already be helping with heat loss. Check around the edges as you can have draughts coming up between the ends of the floor boards and brick walls and then under your skirting boards.  I would prefer to fit something like Kingspan of other fire retardent foam in between the joists. Fit a tight as you can between the joists and stick them up to your floor boards with No-Nails or grip fill. Go around the edges and joints with silicone to seal and stop draughts. No need to go overboard with the thickness as this is to stop the cold air rather than heat loss. As for the grate then if it is safe to suspend something like a slab over it I cant see why wouldn't work. How about a couple of pieces of 22mm copper pipe, or if you have the ability to cut the slab then four peices of slab on each corner? Leave some of the joist exposed and dont over board. The joist needs a circulation of air or you will promote rot. Edited December 2, 2009 by retired Spelling mistake! Share this post Link to post Share on other sites Share this content via...