Timber Frame Planning - HELP!

[willtd]

Hi

I want you to imagine the following room. An internal lathe and plaster wall 5 metres long with an brick wall 4 meters long backing onto next door, at a right angle to the first wall and finally a third wall, exterior made of stone, forming the sloping side of a tiangle between the first ywo walls.

Now, I am going to lower the ceiling and I thought I would attach a perimeter frame using rawbolts into the wall. First question is can these be used on Lathe and plaster.

Then I was going to use joist hangers to form a network across the ceiling, but I now realise that I will not be joining two parallell edges - what will be the best way of fixing the joists across the ceiling?

I hope you can help

 

[TexMex]

I would probably use something like "I cant believe its not nails", to hold the frame to the lathe and plaster wall. I wouldn't want to put any load on it however.

Assuming you are intending to put a plasterboard ceiling in, I would run the joists parallel to the lath and plaster wall with one joist running very close (say within a couple of inches) to the lathe and plaster wall. Unfortunately this would make your longest joist about 5 metres. Unless you can get some extra support from the existing joists above, you would need to use something pretty hefty (say 8x2).

You would also have the problem of the joists meeting the stone wall at an angle of 38.65 degrees. If you want to use joist hangers, you'd probably have to get some sheet steel and make them up yourself.

 

[legs-akimbo]

Can not quite picture what you mean but as far as rawl bolts are concerned try 5" tens on compression anchors, cheap easy and super strong, only way to fix to lath and plaster is into the 4x2 studwork only.

 

[willtd]

HI

What do you mean about the lath and plaster wall?

My concern is that the room is triangular and so I cannot run the timber across the width of the room using joist hangers?

 

[willtd]

. Unless you can get some extra support from the existing joists above, you would need to use something pretty hefty (say 8x2).
.

How do I attach the new 4x2 joists to the 'real' joists behind the current ceiling? I am OK to use screws?

Also what difference would 8x2 make?

 

[TexMex]

How do I attach the new 4x2 joists to the 'real' joists behind the current ceiling?

The best method would be steel straps. You would, of course, have to make holes in the existing ceiling to acheive this, but you don't need to worry about that eh? If you are using 4x2 you would ideally have it supported about every 6ft.

Also what difference would 8x2 make?

Due to the extra strength, it would be less liable to sag, you could therefore increase the distance between supports, upto about 5 metres, hence, no need for extra support from the existing ceiling. This method, would be more expensive (in timber) and place more strain at the fixings on the wall.

My concern is that the room is triangular and so I cannot run the timber across the width of the room using joist hangers?

If you followed my scheme, you would have joists at 90 degrees to the brick wall, (you could therefore use conventional joist hangers here).

Where these joists meet the stone wall, they would meet it at 38.65 degrees, so your average, run of the mill, joist hangers wouldn't do the job. You could, however, fasion joist hangers to do the job from sheet steel. It's just a matter of cutting out the appropriate shape, drilling it, and folding it.

 

[willtd]