structural lintels

[whatarascal]

where can i find ,if at all,a calculator program to work out the required size of a lintel for an outside wall.Or even someone who wont rip me off.
I have been quoted £450 to design a lintel to carry the weight of a wall.
The work to be done is build a rear extension and then knock through to make a kitch diner.
Surely there is money to save on this quote

[Perry525]

If you take a line at 45 degrees upwards from each end of your proposed opening, that area represents the load your proposed lintel will carry.
A typical masonry wall weighs in at around 45 kilos per cubic foot. Above this space the load will be spread over the length of the wall.
Lintels are available in Wicks etc for all normal domestic work, take a look, they are very cheap to buy.
Keep in mind, you have to get it home, move it into place and support the existing wall while working. Have you the right gear to do it all safely?

[LCL]

The triangle of load above an opening is true, unless of course there are joist loading or any openings within the triangle.

Best get in professional advice, it will cost a lot more than £450 to rebuild part of a wall that collapses or significantly moves due to an inadequate sized lintel!!

[Chris Langham]

Whatarascal,

To know what sized beam etc required to carry any loading, you have to specify the loadings themselves.

You must specify the material loading and the live loading before you can have any quantified idea of what 'size' to use. (that involves working out among other things, deflection, shear etc)
To do the job properly, a set of design calculations should be submiited to the Building Control Dept, especially with structural work like you have.

[TheDoctor5]

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