DIY Doctor UK DIY Forums

Hi - I've had some building work done and they've taken walls down and put steels up, including some box steels with 10mm plates welded on the bottom, above the new bi-folds.

I'm fireboarding the steels before BC come to inspect again and I'm happy how to do the I-beams (wooden noggins etc) but I'm not sure how to attach the board to the side and underside of the box steels.

I've got 15mm fireboard so it only needs one layer but I don't think there's enough room to batten the steel with self-drilling screws then attach to it as it will fowl the top of the door. The builder suggested 'sticks like s***' but I think BC will want to see some mechanical fixing.

Any suggestions would be great.

Hi James1979
Suggest you try a solvent based filler/adhesive like Gripfil, you will have to support the boards temporarily until the filler is set. I’m assuming you are not incorporating insulation between the boards and the lintel.
Regards S

Thanks for the reply and no - no insulation between. That’s what the builder suggested to do will go with that. Do you know if BC will be happy with that or will they expect some form of fixing like screws?

Hi james1979
BC are a law unto themselves and each building inspector will have their own ideas. If you use a solvent based gap filling adhesive you should be ok without fixings.
Regards `S