Hi,
I'm getting conflicting advice for some work I want doing, I and I don't know how to determine who I should listen to.
I want to cut a 1.2 meter wide serving hatch in the wall between a kitchen and dinning room. The wall is an internal 12cm thick cinder-block load bearing wall.
The builders all agree the wall is load bearing, but that's where the agreement ends. I've paraphrased the conversations, but this is approximately what each of the 4 builders have said......
The first one says "the opening is so narrow that no lintel is required, I'll use a disk-cutter to make the opening, line it with a wooden frame (cosmetic only) and the jobs done"
The 2nd one says "A 1.2 meter wide opening requires a 1.5 meter long steel box lintel. I'll use acro-props on the ceilings on either side, cut the opening using a disk-cutter, cement in a steel lintel and then remove the props - the wall above the serving hatch will stay up on it's own accord for the short period that it's unsupported"
The 3rd one has similar plans to the 2nd, but he says "the wall above the opening needs to be supported during the work, so I'll cut an extra hole through the wall above the opening, thread a temporary steel beam through this hole and prop it either end to support the wall (and the ceiling above) whilst I do the work"
The final builder says "A 1.5 meter steel lintel is required, but so long as no-one goes into the upstairs room during the work, I can cut the hole, insert the lintel and let the cement dry without the need to bother with acro-props"
Which builder is giving the correct advice? I've not used any of them before, but one's been trading locally for as long as I've lived here, and the others all have good references on various rate-my-tradesman websites.
Surely there's got to be some way of actually calculating the load in the wall and working out what support is required? All of the builders have just done a visual inspection, scratched their chin for a few moments, and then come up with a completely different verdict!
All help appreciated! I'm very confused!
Thanks