There are two joists in my upstairs extension floor that are 7x1 instead of 7x2 like the others. It's a Victorian house and there used to be a chimney at that end of the room, which they've removed.
If I were to sister another 7x1 without going into the pockets the existing 7x1s are in (no room without knocking through from outside and sliding through), would this significantly increase its strength? If not is there something else that can be done? My current plan was to sister with some M12 bar, square washers and timber connectors. Happy to just screw if consensus is that M12 bar is overkill? My 900x900 shower will be sitting on the corner of the room with these small joists, so I wan't to make sure there is support there.
On a side note, I hope to tile this floor with electric matting underneath. I've bought 18mm wbp ply for it. Do you think this, with the existing 7x2 joists (I will add noggins), will resist deflection enough to handle tiles? I've not noticed any spring in the joists myself but I'm no expert. Floor is 2900 x 2200, so quite small. Would you insulate this floor? I don't think it's normal but seeing as the floor will be heated, perhaps it needs insulation to stop heat escaping downward? Thanks for any tips.
If I were to sister another 7x1 without going into the pockets the existing 7x1s are in (no room without knocking through from outside and sliding through), would this significantly increase its strength? If not is there something else that can be done? My current plan was to sister with some M12 bar, square washers and timber connectors. Happy to just screw if consensus is that M12 bar is overkill? My 900x900 shower will be sitting on the corner of the room with these small joists, so I wan't to make sure there is support there.
On a side note, I hope to tile this floor with electric matting underneath. I've bought 18mm wbp ply for it. Do you think this, with the existing 7x2 joists (I will add noggins), will resist deflection enough to handle tiles? I've not noticed any spring in the joists myself but I'm no expert. Floor is 2900 x 2200, so quite small. Would you insulate this floor? I don't think it's normal but seeing as the floor will be heated, perhaps it needs insulation to stop heat escaping downward? Thanks for any tips.
