Concrete vs "internal" lintel

[rjm2k]

I'm going to be cutting through a 100mm blockwork wall to install a new doorway, the wall is only supporting joists above. I see that wickes for example do a 1.2m Lintel in either concrete or a metal "internal" lintel for about the same price. The concrete version is 100m which fits in with the depth of the blockwork, the metal one doesn't have its depth listed.

I'm tending towards the concrete version but wonder what the advantages of the metal one are, I guess it's basically that you have to cut out less material in order to install and it's also lighter so easier to handle? Anything else?

Thanks

 

[noseall]

the wall is only supporting joists above.

Only?

You should be ok with a concrete lintel provided that the joists are not bearing directly onto the lintel, rather there is the lintel then some masonry then the joists.

Also make sure none of the joists bearing above the lintel are not bearing a series of trimmed joists or that there are any unusual loads.

A metal lintel would be a box and be just as awkward to fit as a concrete fella.

What you must have seen was a simple corrugated doorway lintel.

 

[rjm2k]

Yes it was corrugated, what are they used for?Look very flimsy

 

[stuart45]

Yes it was corrugated, what are they used for?Look very flimsy

Only to support the blockwork to the ceiling, not load bearing for joists.etc.

 

[tony1851]

noseall; if he uses a 100 p/c conc. lintel, it will probably be the 65 deep ones. I'm not sure those are ever intended to be other than composite (ie built in as work proceeds) and not really suitable for putting in breakthroughs. They also crack easily if not handled carefully.
If I was doing that job, I'd be inclined to use a piece of 4x4 timber
(eg a piece of fence post). I know this goes agains tthe grain (no pun intended!) but timber is light, strong, flexible, cheap and easy to fix plasterboard to.

 

[^woody^]

Concrete will be fine. The corrugated metal ones are intended for new work

 

[rjm2k]

I think we'll be using reinforced concrete which is what I had planned for initially (I don't even have wooden fence posts for my fence!), was just curious when I spotted the corrugated lightweight version so wondered what they were for.

Bit of a false economy since retail at least they are the same price, though it looks like the corrugated one will simply fit in the mortar line and therefore need no extra cutting work on the block?

 

[^woody^]

The corrugated ones are about 25mm deep and mess the coursing up. And they bend when laying on them. Crap basically.