Door casing

[marsaday]

I have to get a case for a new door in my attic.

The wall is 240mm thick and so i wondered what wood i should use as i dont think you can buy a casing this size.

i am also assuming something 10mm thick will be ok to hang a door off ?

 

[DAZB]

Width of the casing is not crucial as you just centre it in the available 240mm width and as a rule 10mm will not be enough as your hinge screws will go through it and hit the wall. A standard door casing will be around 25-30mm.

 

[marsaday]

I see, so the rest of the frame after you get the casing centred is done in plasterboard.

So do you still use architraving around the entrance to the door. You will have the architrave, then some plastered wall and then the frame. So 2 different colours used as well.

am i wrong with this ?

 

[marsaday]

View media item 32535
View media item 32536
enclosed are 2 pics. if i use a thinner casing, say 10mm. i could still build off from the very strong door frame in the pic (it will actually be a king post i could build off.

So i attach the 240mm x 10mm to this created frame and then screw the door to it and through into the frame. does this sound ok or is it not possible.

i can use a std casing, but i will have to go down to a smaller door size.

 

[joinerjohn]

I'd use a standard door casing and fix it to one face of the stud wall. (not centrally in the 240mm space.
Like this...

Untitled

• joinerjohn
• 29 Mar 2011
• 1

The bit that's left can be plasterboarded over to return the other face to the casing (door casing in orange in the drawing)


Architrave can be fixed to one side of the door casing and something like quadrant to the other side.

 

[marsaday]

ok. do you screw into the main section of the casing (the thicker part)?

 

[joinerjohn]

Yes, but only to fix the casing onto the opening. The door hangs in the rebated part (thinner bit). The rebates are usually about 5/8"th thick. If space in the opening is at a premium, you could have the legs of the casing planed down a bit as at least a couple of the screws fixing the hinges would screw into the timber behind the casing.

PS don't forget to drill clearance holes in the casing when screwing the casing to the studwork.

 

[marsaday]

are these door linings in a set size or can they be cut down (so do they come in 3 parts) ?

 

[joinerjohn]

Door casings usually come in three parts. Two legs and the head (top) sometimes they have pre-cut rebates for fitting the legs to the head and some don't so you can alter the size of them.
Usually you make them to a size to suit the door your fitting into them. In an ideal world, the opening you have made for the door lining will be the size of the door + the thickness of the door lining (leaving a little bit for packing out etc, (allows you to correct any discrepancies in the opening)
Ensure the door lining is plumb on either side and the face of the door lining is a few mm past the face of the plasterboard walls (if your having them plastered) And make sure the head is level too. I'd make the height of the opening for the door about 1/2" to 3/4" longer than the door, depending upon what sort of floor finish your putting down (ie laminate or carpet + underlay)
I usually make the width of the door lining about 3/16"th wider than the door that's going in to it (less work to do on the door to get it hanging) But this all depends on the size of the opening you have made in the stud wall for the lining to go into. When building studwork I always make the opening slightly wider than the lining that's going into it.(say no more than 1/2")