Is it okay to fill the cavity between 2 RSJ (running parallel) with Expanding foam

[coloured]

Helping someone with some house building work. He has recently had a window fitter that has installed rsj 178 x 102 x 19 siting on each side of the wall as it a solid wall without cavity. Is it okay to fill the cavity between the 2 rsj (I beam) with expanding foam to make sure no ingress of water as he has seen some drops in heavy rain and help with coldbridge too

 

[23vc]

Exp foam isn’t appropriate to stop water ingress. How’s the beam on the outer skin protected from the elements? Normally you’d have a beam on the inner and a flange on outer welded to it

 

[^woody^]

It's OK to do, but it's not water resisting or preventing.

Check the external pointing all the way up to the roof or window cill above if water is coming in through a solid wall.

An external wall water repellant may be an option.

In some cases, a cavity tray is required even when there is no cavity.

 

[coloured]

It's OK to do, but it's not water resisting or preventing.

Check the external pointing all the way up to the roof or window cill above if water is coming in through a solid wall.

An external wall water repellant may be an option.

In some cases, a cavity tray is required even when there is no cavity.

Will get a picture from him

 

[coloured]

Not sure if the water could be from condensation. He's waiting for a builder to see how best they can cover the beam - any suggestions would be welcome.

 

[Alastairreid]

It can be framed, ply, builders paper, meshed and render dashed the same as the house. Odd way your builder has done the steel.

 

[coloured]

It can be framed, ply, builders paper, meshed and render dashed the same as the house. Odd way your builder has done the steel.

He was thinking of putting external insulation foam in the beam and then rending. Can you please indicate the fault with the way it's been done. Thanks

 

[Alastairreid]

As 23vc stated earlier there would normally be a flange welded onto the steel on the inner leaf to carry the brick on the external leaf.
I would have used concrete lintels on that span.

 

[coloured]

As 23vc stated earlier there would normally be a flange welded onto the steel on the inner leaf to carry the brick on the external leaf.
I would have used concrete lintels on that span.

This builder had issues and now that he is paid really couldn't be bothered. There is a beam running parallel on the inside wall too. Bolted together.

 

[coloured]

As 23vc stated earlier there would normally be a flange welded onto the steel on the inner leaf to carry the brick on the external leaf.
I would have used concrete lintels on that span.

Can you please explain this - and how this would have helped and is there an alternative

 

[23vc]

The way it’s been done isn’t necessarily wrong, as said, it’s just more of a pain as the outer beam has to be protected/wall has to be re-finished around it and made to look right.
Potentially better approach is to have a flat plate for the outer skin, then the outer masonry just sits on that, no massive exposed full height beam on outside of house. Make sense ?

 

[23vc]

 

[NorthWest1]

When you have a welded shelf to RSJ, how does the loading work?
If you have a solid wall with stretcher and header brick, isn't the load spread across the two courses ?
I've seen wooden lintel supporting inner course with thin steel supporting outer, to give a 'brick to window frame' look. If the steel corrodes and fails, does the loading just sit on the 4x3 wood, with no issues?

 

[Ivor Windybottom]

Foam will trap water and make the joists rust, definitely don't do it.

That outer steel joist simply shouldn't be there. It's cold on the inside because it's metal.

Prop the wall, leave the inner one as-is, it's already there so no point in messing with it. Replace the outer one with a concrete lintel. Then do some lookalike render over it. You can get away with this as it's rendered. It would be worth getting the cavity lintel IF the outside was brick, but in your case it doesn't matter - you just need anything that can be rendered, so concrete is just as good as brick or block.

Alternatively, as a botch job you could cover it with built-up layers of glued cement board then render but this would be likely to crack and fall apart.

 

[coloured]

@23vc that makes sense now what you are saying about the flange. just for my curiousity, is this how this beams would be fitted the red rectangles being the brick for outer and inner layer.