Front door jamb.

[shanesmith80]

Gday helpful people, I'm at again.

This time it's time to put in a new front door. Originally planned to just replace door but I'm guessing since its so old, the door is only 35mm thick and the door jamb only slightly bigger. A little too small for a modern 40mm door. So new door jambs too?

This is where I'm a little perplexed.

House was built in the 50's maybe 60's at the latest. Double brick walls.

Looking at the entrance way, the external dimensions are smaller than the internal.

Hopefully this is evident in the photo's.



Vertical outside about 50mm.

Vertical inside about 70mm.

Top inside 85mm.

Top outside 40mm.

So it looks to me that the door frame is attached to the inside brick layer only. In saying that I don't think its a single layer on the inside. Its about 200mm from the inside corner to the out side of the door frame.

The whole jamb itself is only about 100mm wide and along the side about 45mm thick back to the rendered wall and 60mm thick along the top to the render.

So I guess the question is, Is the internal brick skin opening larger than the external? Is this how it is/was done? I'm guessing there would have to be a lintel above the opening on the internal skin as well?

Now there is plenty of room on the inside to put in a 140mm door jamb to accommodate door and screen but since they seem to be 30mm thick, will all I have to do is bulk it out another 10 - 20 mm. This would be easy enough to do to get a thicker jamb. I'm not overly concerned about attaching everything and putting the door up, have put up a few doors before but in timber frame houses. I just would like to get a bit of an idea whats behind the quad and door frame before I pull it out. That way I can make sure I have all the necessary materials on hand.

Anyway if anyones got any idea what might be going on here I would certainly appreciate your help.

cheers
Shane

[riverbuilder]

Might be double brick with a cavity? Quite normal construction technique.

[shanesmith80]

Might be double brick with a cavity? Quite normal construction technique.

Yep, definitely double brick and the cavity is about 60 -80 mm.

[TermiMonster]

In solid brick construction, the door frame was put up and the bricks laid to it. It had cleats, the size of the cavity attached to the back of the stile, maybe 3 or 4. These held the jamb in place. It could be central to the cavity (square reveals), or further back (off-set). I have seen some, where the frame butts to the outer skin, but mainly on older places, and especially windows. An older bricky would be able to give you more info. Also, bear in mind that available timber dimensions now, are not the same as in the '50s and '60s, so you will have to fudge it a bit anyway. obviously, you can't hold new jamb with cleats, you will need to use anchor screws or similar. Re thickness of wall, approx 110 for brick skin, plus cavty plus render, =220 +50+?20-30mm =up to 300mm +-.

[shanesmith80]

In solid brick construction, the door frame was put up and the bricks laid to it. It had cleats, the size of the cavity attached to the back of the stile, maybe 3 or 4. These held the jamb in place. It could be central to the cavity (square reveals), or further back (off-set).

This is quite possibly what is going on here. Would there still likely to be a steel lintel on the internal skin? There definitely is on the outer skin above door as its the top of the opening.

have seen some, where the frame butts to the outer skin, but mainly on older places, and especially windows.

This is definitely what it looks like.

Thanks.

[rwbuild]

Yes, there will be a steel lintel bar in the inside skin.
Not all builders used timber cleats in the cavity, a large majority of houses in that era had galvanised frame ties which were nailed to the jamb by the bricky as he laid the bricks usually every 3rd or 4th course so you may have either method used in your house. Another method which may have been used is timber wedges driven into every 3rd or 4th coarse after the bricky has built the inside walls, the carpenter would do this and fit the jamb then the bricky would build the external wall.

[justonething]

Would it be a better option to make a door that suits? These doors are solid core - basic construction is very simple - laminated hardwood with 2 thin layers of ply. This may be simpler and more authentic than changing the jamb.

[Beardy]

The easiest option is to swing another door in your existing jamb, 35mm is ideal but you can also fit a 40mm if you are happy with the look
There will be some 35mm options that are strictly not sold as external doors but you could still use one if you wanted to.

Depends how big a job you want to make out of it really

[rwbuild]

You can get 35mm solid core from Hume or Corinthian via the green shed or M10