Underpinning???? Are they trying to rip me off

Mr_BOOMBASTIC

Hi,

Was wondering if there are any builders out there who can help.

I've been getting a few quotes in from local builders to come round to knock a hole through a wall to join living and dinning room together. All i want is the hole knocked through and the lintel supplied and fitted as i will make good when i replaster. All of the smaller companies have said they will need to come out and have a look before they can quote, however one of the more larger firms have quoted us £1200 over the phone an said the building will need underpinning hence the £1200. Is this true or are they trying to rip us off. I know alot of people who have had this done and none of them have paid for underpinning though i do understand all jobs are not the same. I dont mind paying top dollar for a proper safe job but i work too hard and long to throw money away on pointless work.

So does this sound correct to anyone


Thanks

Ukuser

we had the same done by a local builder to our semi

steel - £180
labour £300 inc materials and plastering

approved by building control

hope this helps

foxwales

When they say underpinning I am assuming they mean getting in some acro prop's to support the floor above whilst the wall is removed; they are taking into account that your wall could be load bearing; in which case if you don't underpin the wall whilst the work is carried out, the structural integrity of your home will be at risk.

For all the work you need along with acro props and a proper rsj the average price seems to be around £1200.

robv_3

You don't mention how wide the hole will be and if the wall is structure.

1200quid to make a 8ft wide hole in a structure wall does not sound to bad. I would expect they gave a guide price as its near impossible to quote over the phone.

Does it include structure calculations and building control fees?

In theory they would need to dig test holes to determine if the foundations can take the weight. Depending on the results of this your 1200quid could become 2000.

The wall above will need to be held up while the work is taking place. These 'acros' can be called 'pins' hence 'pinning the wall up'. Would this be what they said?

olias

It depends on how much load there is above and how wide the opening, therefore how big the steel is. Price of steel has apparently gone through the roof lately. Also need to take into account variables such as access for removable of spoil etc. It's a lot quicker and easier for example if the room is right next to the front door and access for a lorry or skip than if the rubble has to be moved through half a dozen rooms and through a long garden and path to a lorry or skip. Having said all that, average price would be £1000-£1500 with the lower end being if you were to do all the plastering/skirting making good etc.

Olias

Mr_BOOMBASTIC

They ask me for the floor construction as the would need to get through this to the foundations to under pin to avoid slippage

Kiran

Can I assume that your living room and dining room are original and not an extension? If so then all you are doing is removing brick/blockwork. Even if the wall is load bearing there is no reason to assume that it requires underpinning. If the lintel is installed correctly then the loads will be transfered straight down into the existing foundation. The only time that underpinning would be required would be if the wall had been built off the slab which is a no no anyway for a load bearing wall. I fail to see how a company would know this over the phone.

Depending on where abouts in the country you are, I'd say that this price is a high considering you don't require making good. The job should be completed within 2 days depending on the size of the opening.

I would be inclined to get a few more quotes personally!

olias

I agree, I've never heard of underpinning being needed for removing a wall to open up two rooms

Olias

Mr_BOOMBASTIC

House is all original no extensions

The opening would be about 6ft wide and the house is victorian hence the solid no cavity brick wall.

BB1984

I guess that underpinning may in theory be required as you are transferring the load, which has historically gone down through the central wall, into the two "side" walls, the foundations of which would not have been designed to take this new concentrated load.
However, I would be surprised if underpinning was actually necessary, firstly because Victorian houses tended to be over-"designed" in the first place. Secondly, the loads we're talking about aren't actually that high in the scheme of things - and assuming the ground conditions are fine. Thirdly, this kind of building work is carried out all the time in these types of houses, and I've never known underpinning to be necessary. I'm sure some of your neighbours have had the same wall knocked down - is it worth having a chat to some of them?
BB

MX5huggy

quoted us £1200 over the phone

This is where they/you have gone wrong. Get some more quotes from people that actually see the job and can explain to you what needs doing.