What size door lining to span cavity

[Adman101]

Hi
I am building extension at the moment and will be installing door linings soon. Most of the internal walls are the same thickness and am planning to use 133mm wide door linings. However, there is one wall which leads in to a small room which is single storey so the there is a cavity of 100mm on top of the two skins of block. Just wondering what sort of width door lining is best to get a good fix to the block work? I don't really want something that is 300mm wide as this would a bit strange, but wanted as close to 133mm to match in with the rest.

Is it worth wedging some timber in the cavity to fix to? There is a catnic above so cant really fix to that.

Any advice appreciated.

Cheers

Ad

 

[Deleted member 174758]

What about installing a rebated door frame then plasterboarding the reveals? It depends on whethetr or not you want to afdd architraves to match the rest of the woodwork

 

[Adman101]

Excuse my lack of knowledge, but what is a rebated door frame? is it where the door frame thickness is less than the gap it is going in to? i.e. doesn't come flush with both walls it is bridging. I don't want architrave on the door.

 

[Deleted member 174758]

Excuse my lack of knowledge, but what is a rebated door frame? is it where the door frame thickness is less than the gap it is going in to? i.e. doesn't come flush with both walls it is bridging. I don't want architrave on the door.

A door casing is basically made of flat planks which have a rebate worked round one edge (this acts as a door stop) whilst a door lining is made of flat planks to which stop laths (called banging strips in Birmingham, I'm told) are fixed (nailed) round three sides to achieve the same effect. They are both designed to be used in internal door openings, are the same width as the finished thickness of the walls (generally between 90 and 200mm - this hides the reveals) and are normally finished by attaching an architrave moulding round three sides to cover the joint with the plasterwork. This is the "standard" way to accommodate doors in internal rooms

A rebated door frame or door frame is what you'd normally expect to see used in a deeper opening, such as the one your front or back door occupy. It is thicker and more rigid than a door casing/lining, but does not extend to the edges of the opening (front and rear). That means there will be exposed masonry in the opening (called the "reveal") which will need to be either plasterboarded, plastered or in some other way tidied up

 

[Adman101]

Thanks for the thorough explanation. That makes it much clearer now. A rebated door frame is what I want. However, I am a little unsure about how to fix it in the gap. on section, there is 100mm block, 100mm cavity and 100mm block. Therefore if i wanted to fit the door frame in the centre, there is nothing (the cavity with cavity closer) to fix the door frame to. Should i just gripfill it in?

 

[Deleted member 174758]

A rebated door frame is what I want. However, I am a little unsure about how to fix it in the gap. on section, there is 100mm block, 100mm cavity and 100mm block. Therefore if i wanted to fit the door frame in the centre, there is nothing (the cavity with cavity closer) to fix the door frame to. Should i just gripfill it in?

If you fit the door in the centre you will need to fit a door stop as well (to prevent the door from damaging the plasterwork) and the door will not open more than about 85 or possibly 90 degrees. Obviously as the door frame needs to be firmly tied to the masonry it cannot be placed where the cavity is (Gripfill is a complete bodge and in any case would fail pretty quickly) - it will need to be elsewhere in the opening unless there is sufficient width across the opening to allow a series of horizontal battens crossing the cavity to be fixed in place (3 or 4 per side) and to which the door frame would be fixed in turn. I have done this on occasion, but if you've little or no experience in fitting door frames I feel that you'll struggle to get everything plumb, legs in alignment, etc - because you lose the ability to view the frame obliquely to check if the legs are in line (there is a way to do it, but it is more convoluted, and many younger chippies I work with don't seem to know it either). Door frames are normally mounted to one side or other of the opening in the wall to allow them to be more easily aligned and I'd recommend that approach if at all possible

 

[Adman101]

Thank you. Given that advice, I think I will move the door frame to the skin opening in to my utility. I have come across doors that don't open more than 85/90 degrees in the past and have wondered why but that makes perfect sense now. I'm glad I come on here now. Cheers Job and Knock