old buildings wooden lintels

[scottishjohn]

how would you equate wooden lintel sizes to concrete ones

as they all need replacing 

[nod]

A 200 deep concrete lintel will support most 

Though I’ve worked on stone bar conversions with thick stone walls and a row of four 100s have been used over windows and doors 

[scottishjohn]

the original wooden ones seem to about 150mm and 300mm wide 

what Iwas looking for is if anybody knew of a comparison of wood to concrete

Edited June 5, 2022 by scottishjohn

[Mr Punter]

Concrete will carry larger loads over greater spans than timber the same section size.  If you are doing a lot it would be worth getting a decent engineer to spec them.

[SteamyTea]

Here is a timber beam calculator.

 

https://www.timberbeamcalculator.co.uk/en-gb/calculator/timber-beam/british-standards?new

 

Work out what you already have, then look for a concrete one.

 

https://www.naylor.co.uk/products/lintels/lintels-selector/

[scottishjohn]

12 hours ago, SteamyTea said:

Here is a timber beam calculator.

 

https://www.timberbeamcalculator.co.uk/en-gb/calculator/timber-beam/british-standards?new

 

Work out what you already have, then look for a concrete one.

 

https://www.naylor.co.uk/products/lintels/lintels-selector/

that calculator does not list OAK   or teak ,probably from old sailing ships and things at 14" wide and 6" deep 

maybe me ,but I can,t make any use of it 

 and how do i calculate the load of the granite stones on top of it -- Iwas looking for a rtaight foreward com[parison .

will probably just replace wood  oneswith pre stressed lintels to make up same dimensions ,maybe 3 or 4  wide where needed

 

 

Edited June 6, 2022 by scottishjohn

[SteamyTea]

https://www.engineeringtoolbox.com/wood-beams-strength-d_1480.html

 

1 hour ago, scottishjohn said:

how do i calculate the load of the granite stones on top of it

Measure the size to get the volume, multiply by the density, then multiply by gravity.  That gives you the force in Newtons.

Then measure the width ad length of the lintel, in meters, to work out the surface area.

Then divide the N by the m² to get the N.m^-2, AKA pascals.

 

Edited June 6, 2022 by SteamyTea

[George]

I wouldn't try and compare timber to concrete. Just assess each opening on its own merits compared to the load rating of the lintel. 

 

The lintel manufacturer or a structural engineer can assist with this.