Beam installation for a bi-fold door. 3000mm wide.

Hi John, You need to get a "Catnic CXL240 Extreme Load Lintel 3500mm length" which gives you two end bearings of 200mm on the brickwork. You'd also need 5 acro and strongboy, spaced out at 900mm, two at ech end and three in between to support the load above while work goes on. A good brickie would finish the courses above and you can take the acros out 48 hours after laying new bricks. Price wise you need to shop around. Good luck 👍 James

Hi John It is always advisable to get an engineer to spec the supporting steel, especially if you’ve an opening as wide as 3500mm.I personally would not take on a job that didn’t have a structural engineers calcs. I’m guessing the 25mm brick wall width is a mistake as a brick wall with cavity is going to be about 275 - 315 , but the engineer would pick that up when designing the supporting steel work, which would probably be in the form of a beam and plate to pick up both the inner and outer skins of the brick and block work. It will need to be a minimum of 300mm over length to give the minimum bearing of 150mm each side. It is worth shopping around when sourcing the steel as some companies will supply and fit over the opening, which is worth considering with a large structural steel of that weight. Support timber would not be required, everything would be in block and brick work, a good brick layer should be familiar with the work and the bedding down of padstones ready to take the steel work. I would estimate a cost of around £2500 plus the steel cost, to make the opening, provide temporary support to the building, install the steel work and carry out associated brick work.Also there would be a fair amount of rubble to dispose of.

Hello john, firstly I'm hoping the 25mm thick wall is a typo since bricks are 100mm each plus cavity. That aside i would definitely get an engineer to spec the opening, i have seen some awful guesses used . You can go with either the above mentioned catnic or a galvanised ( as it's exterior) universal column steel with a full width plate welded underneath to pick up the outer skin, almost all extensions i now do spec a steel and plate and you'll require at least 150mm bearing each side. strong boys will work so will needles, i prefer needles as i get more space to work in and a cavity damp /tray is needed over the lintel. pricing material, once you get the requirements call around for the best price obviously. yes i would use a recommended bricklayer and or builder. no support timber is needed as strong boys/needles do this very well. labour cost is like how long is a piece of string, more info is needed especially things like accessibility and what you are prepared or wanting to do yourself, off hand 3-5 days work for at least two men... good luck.