Cavities Covering Surrounding the Patio door

[Mahmud]

I have just had a small extension (approx 3 x 3.5 meters). The builder has done some nice work and I have no complaints. Unfortunately the builder is foreigner and therefore does not have all knowledge and I am not a builder myself.

My question is how do we go about covering the cavity which has been left on the side walls and on the floor near the patio door? A new patio door has been fitted on the external wall and the new screed floor is about to be laid down.

Can someone advise how the cavity on the side walls surrounding the patio door should be covered before plastering and how the cavity on the floor (above DPC) should be covered before laying screed floor and how can the metal lintel above the patio door be plastered?

 

[Richard C]

Can someone advise how the cavity on the side walls surrounding the patio door should be covered before plastering and how the cavity on the floor (above DPC) should be covered before laying screed floor

Cavity closers.

and how can the metal lintel above the patio door be plastered?

I assume your talking about the underside of a Catnic type lintel! Either base plaster to around 10-12mm thick with Bonding plaster, stick some edge beading around the reveal & then finish skim with Multifinish plaster

or (my preferred method)

Stick some 12mm plasterboard onto it with grab adhesive, stick some edge beading around the reveal & then finish skim with Multifinish as before.

 

[noseall]

as per above really.

after fitting the cav closers, we dab a plasterboard to the reveals and the catnic underside. try pulling it off and you'll see how good it is.

as for the screed, we always remove the top course of bricks from across the door opening and use a piece of dpm against the remaining masonry and screed over. if you don't remove this course of bricks then the screed will probably crack away as it is usually too thin at this junction.

incidentally, we always lay 525mm of masonry onto our foundation because this always means having a course of bricks as the last course before dpc. this allows us to remove the bricks in external doorways.

tough luck if you have a course of blocks.

 

[^woody^]

Dont waste money on cavity closers, use a strip of DPC and expanding foam to fill the cavity at the edge. Then board over it.

For the screed, do as mentioned above, but consider placing a stip of 10mm or 25mm insualtion between the screed and the inside face of the external wall to prevent a cold bridge and condensation issues.

I like the fact that these foreign builders don't know how to do a complete job

 

[mikric]

Dont waste money on cavity closers, use a strip of DPC and expanding foam to fill the cavity at the edge. Then board over it.
Check the requirements with building control you will need a pre plaster check any way. We used to be able to use lots of different methods ,kingspan jablite etc but now they will only pass a purpose made closer in my area. £££££ that is if bco is involved of course .