I am building a concrete workshop which will have a doorway 1.8 m wide. I am looking to put a concrete lintel above this which will support a single coarse of blocks and the flat roof. Would a 100 x 65 lintel be sufficient given that there is very little weight above or should I go bigger. Any advice greatly appreciated
Is it single single blocks or a cavity? Put in a 140×100mm lintel ast year, they are heavy! Plus will need ideally 150mm overhang each side. So put 300mm on top of opening.
I put in a concrete lintel last year, on the floor to support a wall above so it prevents movement. Wanted a 2.4m x 65 x 140, they only had a 2.4m x 100 x 140. Two of us could just lift it. Perhaps 100 x 100 and 2.1m long? https://www.condell-ltd.com/prestressed-concrete-lintel-textured-finish-s10-100x100x2100mm
Its single skin, but there are pillars either side of doorway. It is the weight for getting it up there I was worried about. That was why I hoped as the load is only I couse and the flat roof, the 65 might have been sufficient
An S10 100mm x 100mm x 2.1m prestressed concrete lintel weights 48.1 Kg, not so bad. Mine was heavier as it was 140mm wide. https://www.supremeconcrete.co.uk/p...els-and-padstones/prestressed-premium-lintels
A 65×100 prestressed lintel wil be more than ample. Builders merchants I have found usually only stock 65×100 or 100×140 lintels.
140 x 100mm lintel bedded plus 1 course of concrete common is 1 block course in height, whereas if you use a 100 x 100mm you need to cut blocks over the lintel.
Ok so you mean put lintel in 140 mm upwards with a course of common blocks on top. Would tie in with a course of standard blocks either side of the lintel?
Have decided to go for 100 x140 to be on the safe side. I was advised to build piers for the doorway for strength but after I had already put in foundation. If I install them, the piers are going to overhang the main foundation by about 15mm internally. They will be sitting on 100mm deep concrete floor for that 15mm though. Do you think that will be Okay?