How to pack floor joists?

[pilsbury]

Pretty much as the title. Going to be putting 225x47 joists in the loft. They will sit on external walls and mid point on supporting walls below.

Mid way in my loft is a massive 300mm steel that will be not used in floor support, but obviously I want my joists to sit fractionally above this.

What's an appropriate method to raise these joists? Brick? Wood bedded onto the walls?

 

[KenGMac]

pilsbury, good evening.

At one time Slate was a good bet, did not compress or rot

High density plastic shims uniform in thickness, various thicknesses And you can nail right through them.

Ken.

 

[pilsbury]

I've got to pack approx 75mm

 

[catlad]

If your not using this massive 300mm beam for supporting your floor, what is it doing?

 

[KenGMac]

AAAaaa

Is there a wall plate in place now?

Timber packer on top of the wall plate? all treated timber with suitable hold downs in place?

Ken

 

[pilsbury]

If your not using this massive 300mm beam for supporting your floor, what is it doing?

Runs front to back sitting on external walls. Has brick piers built off it that support the purlins.

 

[pilsbury]

AAAaaa

Is there a wall plate in place now?

Timber packer on top of the wall plate? all treated timber with suitable hold downs in place?

Ken

Wall plate on external walls that the current 4x2 ceiling joists sit on. Nothing on the mid point supporting wall. Just brick that sits level with the lath and plaster.

As I'm typing I'm realising that raising the mid point supporting wall 75mm merely requires packing of some sort. But raising the external wall plate is going to be an issue with roof slope. I.e there will be no gap for a bearing of the new joist

 

[catlad]

Ok so is it a hip roof? If you are trying to get over this you can build up the central wall .

 

[catlad]

Pole plate with your new floor joists cut to the pitch of your roof, and then bolted to your rafter feet whilst sat on the pole plate. If that makes sense?

 

[pilsbury]

Ok so is it a hip roof? If you are trying to get over this you can build up the central wall .

Gable one end, hipped the other. But for the area I’m talking about, gabled.

 

[pilsbury]

Pole plate with your new floor joists cut to the pitch of your roof, and then bolted to your rafter feet whilst sat on the pole plate. If that makes sense?

Is this what you’re on about. Got my crayons out.

 

[catlad]

Yep! but you do need to practice with those crayons more.