Lintel lenght

clint_eastman

quick question or 2,

whats the standard overhang on each side for concrete lintels over doors, windows etc?
also, at what point should an rsj be considered instead of a lintel with regard to larger opes? is there a rule of thumb? have some large opes in the hallway, approx. 3.5m.

Thanks.

mr_edge_to_you

Hi Clint, I'm no expert in this regard at all but I would strongly advise that you discuss those issues with the engineer who is signing off on the stage payments. Ultimately it is his call. We've gone for concrete floors upstairs over an open plan downstairs. Our builder asked the engineer to sign off the spec he put together to ensure there was ambiguity. I know this isn't exactly the answer to your query but his/her input will be required. Cheers, edge.

clint_eastman

Thanks!

I agree fully and will of course be running everything past the engineer for approval beforehand. I'm pretty much just looking for guidelines for pricing purposes e.g. for a 1m wide window should i be looking at pricing a 1200mm lintel and so?

Appreciate the input Mr. Edge.

paudie2005

clint_eastman wrote: »

Thanks!

I agree fully and will of course be running everything past the engineer for approval beforehand. I'm pretty much just looking for guidelines for pricing purposes e.g. for a 1m wide window should i be looking at pricing a 1200mm lintel and so?

Appreciate the input Mr. Edge.

to my knowledge the minimum bearing either side of the ope is 150mm, so you'd be looking at a 1300mm lintel minimum

mickdw

225mm bearing each side is best.
In relation to spans, dont go over 2.5m with the standard 100 x 65 prestressed lintel.
Dont forget also that these lintels must only be used as part of a composite structure, i.e. they are relying on the bond with the blockwork overhead for strength.
You should also look out for any point loads loading these lintels and take appropriate action

YourAverageJoe

Lintels are not that dear so I went for 200mm bearing. Anything over about 3m I used steel and anything supporting concrete floor above I used concrete lintel with steel positioned two rows of blocks above it. I have seen concrete lintels used for garage doors so they must be about 3m or more?

clint_eastman

Thanks guys. I see from TGD A that 150mm is the minmum but its good to get your opinions given that i'll also have a concrete 1st floor and upping the bearing spec would be no harm given the low costs involved.

gman2k

Blocklayers down my way went for 300mm extra either side.

soldsold

My blocklayers wanted to put in the dpc (for over the windows) on top of the lintels but as pointed out above this makes the lintels weak so I made sure they used wider dpc and placed it at least a block up

RKQ

clint_eastman wrote: »

Thanks guys. I see from TGD A that 150mm is the minmum but its good to get your opinions given that i'll also have a concrete 1st floor and upping the bearing spec would be no harm given the low costs involved.

I really think you need immediate Professional advice.

Mickdw is quite correct and I would recommend you retain a Structural Engineer to work out loads of Conc 1st floor and specify lintels.

<no specification of structural evements>
Mod Edit: The user has been infracted for specifying structural elements on thread in breach of forum charter.

RKQ

<snip>
RKQ I will not argue with you on thread. You clearly breached the charter for which I gave you an infraction and if you attempt to derail this thread any further I will ban you, you have now been warned.

RKQ - do not delete this again - sinnerboy

clint_eastman

ahhh...thanks for all the advice guys, really much appreciated, not too sure what the above is about but anyway! To be honest i was really just trying to get an idea so i can get some prices together. I'm an mech eng so not really qualified to spec anything to do with the structural element of the build but I'm definately able to develop budgets based on estimated materials specs....my intention will be to get my civil eng (when appointed)to do the final spec for the lintels and rsjs needed. For now i'm just going to use 200mm as a basis for pricing and go from there. Thanks again!

muffler

clint_eastman wrote: »

ahhh...thanks for all the advice guys, really much appreciated, not too sure what the above is about but anyway! To be honest i was really just trying to get an idea so i can get some prices together. I'm an mech eng so not really qualified to spec anything to do with the structural element of the build but I'm definately able to develop budgets based on estimated materials specs....my intention will be to get my civil eng (when appointed)to do the final spec for the lintels and rsjs needed. For now i'm just going to use 200mm as a basis for pricing and go from there. Thanks again!

That is indeed your best route

There are minimum bearing lengths that can be found in many good books such as the Homebond House Building Manual or in the Technical guidance documents. However to achieve the correct dimension specific to your proposal you do indeed need to engage a structural engineer or equivalent.

Good luck with it.