Fitting internal bi fold doors to larger opening

[Fishcakes]

Hi everyone,

The opening is approx 15cm larger than the door including the frame. The doors are top hung so will need to be secured to something strong.

My instinct is to get a piece of timber and screw it into the lintel above to secure it, then fit the door to that? I'm not sure if this is safe to do?

Alternatively does anyone know any good joiners/carpenters in Nottingham who could do this if you believe it's too complex for DIY?

During renovation, it's a concrete lintel?

Opening size

Example from website

 

[freddiemercurystwin]

You could just build a solid timber framework packing inside the opening and then plasterboard over then plaster it so it was flush, then over paint, nothing more complicated than that.

 

[catlad]

As per Freddy
Build a timber frame in the recess that can be clad / sheathed in osb 11mm and finished in plasterboard if desired.

 

[Fishcakes]

You could just build a solid timber framework packing inside the opening and then plasterboard over then plaster it so it was flush, then over paint, nothing more complicated than that.

Hi Freddy thanks for the reply, too be honest that was my initial thought, wood, plasterboard, plaster, paint to make it look like part of the wall.

Could you maybe expand on the timber framework? I have no issues screwing wood to surrounding brick work on the sides, but how do I fix the wood to the lintel?

Are you suggesting building a hollow timber box or would a single solid piece of wood be better? I was thinking using those large bolts recessed into the wood and into the lintel?

 

[freddiemercurystwin]

What kind of lintel is it? Steel or concrete or maybe timber? You need to find out, probably by making a hole in the plasterboard underneath the lintel, that all has to come out anyway.

 

[Fishcakes]

What kind of lintel is it? Steel or concrete or maybe timber? You need to find out, probably by making a hole in the plasterboard underneath the lintel, that all has to come out anyway.

I think it's concrete but prior to us moving in there was a black decorative faux beam stuck to it with large nails so it's possible it could be wood.

No point speculating, I'll drill into it tomorrow and then go from there.

 

[Fishcakes]

As per Freddy
Build a timber frame in the recess that can be clad / sheathed in osb 11mm and finished in plasterboard if desired.

Hi mate, could I screw some blocks into the corners then build the rest of the frame by screwing timber/OSB to the blocks to make a hollow box? Or would that not be strong enough?

I think I'm over thinking this, I just don't want to drill into the lintel and then the whole thing falls down.

 

[freddiemercurystwin]

First things first, find out what the lintel is. A solid timber packing will be better.

 

[catlad]

Hi mate, could I screw some blocks into the corners then build the rest of the frame by screwing timber/OSB to the blocks to make a hollow box? Or would that not be strong enough?

If I was building this I would use 3x2 timber. I would glue a piece centrally on edge to the underside of the lintel ( expanding foam works well ) if you can clamp it in position for half an hour till it sets. then I would cut some short lengths about 10 inch at a guess. Fix two of these small pieces to the side walls under the 3x2 you have already fitted, once you have done this fit a bottom rail the same as the top one so you have an oblong box, you can then fill in the box with the other small bits of timber spacing the equally. Once you clad this in osb you will have built a box lintel which you can finish with plasterboard.

 

[catlad]

The osb will need to be glued and screwed with plenty of say 50mm x 4mm screws