Interior Lintel in a timber stud / brick infill spine wall

[rikmayall]

Hey guys, I'm a Structural Engineer doing a simple design on a friends 1890 built house (London) for a structural beam to span between what I thought was an internal brick wall... the builder uncovered the plasterboard earlier and exposed a timber stud brick infill wall.

I'll need to get called over to the site at some stage tomorrow but I am a little worried now that the brick is doing no work at all, and is just acting as sound / insulation between the rooms and also some restraint for the timber vertical studs. It means I'll have to start adding/replacing timber beam sections to make sure they can take the load, as well as the posts to take the axial loads from the new lintel.
Has anyone had any experience with timber infill walls and any solutions or to suggest what best way to approach this?
Can I introduce a beam and start loading up the brick on either side? Does the timber stud usually run the full way down to foundation or doe the sole plate of the stud wall normally stop at ground floor level? Can I assume that the brick will take some axial load from the beams if there is contact between the beam and the top of the brick infill??

 

[tony1851]

Conventional brick-on-edge partiitions don't usually go down to foundation level - they are normally supported off the floor.

Without knowing your loadings from above, it's not possible to say whether or not the remaining brickwork at the sides will be sufficient to take the load.

How thick are the bricks? 65-70mm? you will have to check the slenderness ratio first. My guess is it will be somewhere near 25 - 27 (assuming an effective height of 0.75h). This means your beta will be on the low side (prob. 0.4 ish). You then need to assume an fk for the brickwork - you will need to be conservative on this - say something like 4N/mm2.

If your loading is not too high, you might just make it. But then you will need to check the supporting structure at the base. Which way do the floor joists go - you will need to check those for bearing and shear as well. If it did make it, you would be pretty near the limit and is it worth the risk?

Prsonally, I'd be inclined to take the whole thing down and repace with timber studwork at the sides - that would more reliable to calculate. Don't be pushed too much by your friend's need to economize - it'll be your name on the figures.

 

[freddiemercurystwin]

I'm a Structural Engineer

So why you asking here?

 

[rikmayall]

I'm a Structural Engineer

So why you asking here?

So when someone becomes a structural engineer they know everything about all structures ever built? Get real.

Came here for constructive replies, thanks.

 

[freddiemercurystwin]

I bet your friends don't know you're asking for advice on a diy forum do they!

 

[rikmayall]

I bet your friends don't know you're asking for advice on a diy forum do they!

Im looking for some information, preliminary advice.
I'm gonna do the calcs for building control to prove it works. Some opinions from an experienced builder on what the cheapest/easiest solution would be, would be helpful.
Seriously catch a grip.

 

[freddiemercurystwin]

I've caught a live one!

 

[tony1851]

What load is it actually carrying? Surely as it's a partition, there won't be any floor joists supported off it? And your beam seems to be right up against the ceiling.

IMO it's just a case of stability - and I personally wouldn't like to leave a loose panel of brick-on-edge flapping about each side. Just replace the side bits with new studwork and plasterboard and have done with it.

 

[noseall]

Agree with Tony, remove the lot and start back at the beam.

It may be prudent to have the steel fabricators drill some staggered 10mm holes in the bottom flange to allow you to bolt say a 100mm x 50mm timber to the bottom of the beam.

We always have holes drilled in the web as to allow us to bolt in a timber sandwich either side. Makes cladding the beam easier.

 

[rikmayall]

What load is it actually carrying? Surely as it's a partition, there won't be any floor joists supported off it? And your beam seems to be right up against the ceiling.

IMO it's just a case of stability - and I personally wouldn't like to leave a loose panel of brick-on-edge flapping about each side. Just replace the side bits with new studwork and plasterboard and have done with it.

Cheers for feedback guys.

It's spine wall taking the load from the first floor and attic. The first floor wall is timber stud but doesn't have the brick infill.

I've thought about it a little more. I'm going to be taking out 3 internal vertical timber posts so will build two new masonry piers either side to take a new steel beam which will sit supporting the existing timber header beam. I can't rely on any structural stability from the existing brick. Only issue really then would be propping that existing header beam which will be taking all that weight from the upper floors!

 

[RonnyRaygun]

I've thought about it a little more. I'm going to be taking out 3 internal vertical timber posts so will build two new masonry piers either side to take a new steel beam which will sit supporting the existing timber header beam. I can't rely on any structural stability from the existing brick. Only issue really then would be propping that existing header beam which will be taking all that weight from the upper floors!

I've seen this a lot in traditional London stock.

Why not sister the remaining studs at the edge of the opening, and ply the remaining wall which will give you all the stability you need. I'm sure that the home owners would prefer that compared to having new piers built. It would be a lot cheaper too.

I don't know whether you would get a timber beam to work, so you might still need a steel above.