Do I need to replace interior wooden lintels?

[b00gieman]

I am replacing two windows in a victorian house from wooden sash windows to PVC windows. The windows are on opposite sides of the house with a stone outer lintel and wooden internal lintel - solid walls with no cavity. Both stone lintels have recently been replaced.

I imagine the internal wooden lintels will need to be replaced when I remove the wooden sash windows (which I imagine are partially supporting the lintel) as the lintels are about 185cm and joists sit directly above them. At the moment the wooden lintels look fine.

I have taken a few pictures to show the windows:

Window 1:

Window 2:

Do you think they need replaced? If so concrete or steel?

I probably won't tackle this on my own so any suggestions of people near Leeds that could help would be very welcome!

Thanks!

 

[^woody^]

Yes change them, there is already a damp issue there by the looks of things.

Concrete or steel or don't matter

 

[b00gieman]

Yes change them, there is already a damp issue there by the looks of things.

Concrete or steel or don't matter

Thanks Woody. I had a builder come round to quote and he said he would fit 140 X 100mm concrete lintels but yesterday when he did the job he fitted 65 X 100mm. These look a little small to me but he assured me they would be fine. The openings are about 160cm on both windows.

Is this right?

 

[tony1851]

It looks to have bowed a little in the middle, and the ends seem supported off bricks mortared in on end?
Thin concrete lintels are not ideal for point loads from the floor joists - a 140 deep lintel would have been better, but the joist ends would have needed to be notched or fixed on hangers.

 

[^woody^]

That lintel should not be bowing.

"Prestressed" lintels are available and these are bowed, but the bow goes upwards. But as is, that is concerning. If it's a roof above, then account needs top be made of snow loading in the winter, so if it's bowing now .......

The bearings are inadequate too - should be longer, and this may account for the bowing.

The sides are a mess. No way should bricks be stacked like that with no bonding in. And worse of all, no way should a lintel be placed on stacked bricks.

 

[23vc]

Cut thermalites up the sides supporting the lintel... that’s a new one on me. Wow

 

[23vc]

Re. The Bowing, I know it looks like it is, but I was trying to work out if it’s actually The upvc frame distorted the other way... would be less scary if it was.

 

[b00gieman]

I caught a look at the lintel before it went in and the sticker said it was prestressed. It is bowing in the middle and a hairline crack has appeared in one of them. The joists are supporting the floor above.

The thermalite bricks were put in by me, not for support but for filling the space where the sash window weights were (as pvc windows are now in).

I'm guessing 140mm should be in there?

One one side there is not enough space between the joists and top of the window opening for 140mm, there is only 100mm. Would steel be better there?

I'll go back to the builder tonight and get him to change them.

 

[^woody^]

Bowing like a 747.

Yeah, get them changed.

 

[b00gieman]

Can you recommend any sites for learning about calculating loads and lintel sizes?

Wondering if a high strength 100 X 100 would do on one side and 140x100 standard on the other. This would save me notching into the joists which I know isn't allowed or having the internal lintel cover the top of the window on the outer skin.

Thanks.

 

[b00gieman]

Can you recommend any sites for learning about calculating loads and lintel sizes?

Wondering if a high strength 100 X 100 would do on one side and 140x100 standard on the other.

Thanks.

I have found a concrete lintel supplier close to me (Naylor) and they state that the Unfactored Load (kN/m) for their Economy 140x100x2100 lintel is 4.81kN/m and for their Hi-Spec 100x100x2100 lintel is 5.02kN/m.

I just need to work out if 4.81kN/m is strong enough.

If the opening is 1.6m, that would mean the triangular area above it is 1.28m2 (0.5x1.6^2)? Not sure how much a single skin of Victorian bricks weigh per m2 or how to factor in the joists for the floor above.

Should I call a structural engineer at this point?