Home Property GuidesProperty Insights & Advice What you need to know about knocking down a load-bearing wall

What you need to know about knocking down a load-bearing wall

by John Saunders
14th Jan 20 11:06 am

Programmes like Grand Design and To Build or Not to Build have attracted a large audience of people keen to take up DIY projects at home. Projects that include building a house from scratch or becoming involved in home renovations.

Even if you don’t do the work yourself it’s handy to know what your builder is going to do for you. As an example here is some information about creating extra space. If you don’t want to move then knocking two rooms into one or indeed changing the layout of your entire home is a good solution.

But, before you run out and buy a sledge hammer or contact a builder sit down and make some plans.

You don’t normally need planning permission to knock down walls, but you may need to contact your local building regulations department to make a building regulations application.  If this is the case you will have to comply with building regulations. Once the work is finished building control will come and inspect the work. If everything is satisfactory you’ll be issued with a certificate.

If you’re only changing one room then get yourself some squared paper and make up your own floorplan. If you’re project is bigger ask an architect to draw up a floorplan so that you have exact measurements of the rooms throughout your home.

Next, decide what you want. Are you thinking about making the whole ground floor an open-plan space, or are you knocking a wall down to create one large room? Once you know you want then make a note of where your utility cables and pipes are situated. They may need to be altered.

After this, you should ask a structural engineer or a builder to check if the wall you want to remove is load-bearing. He or she will check the roof, the floor, upstairs walls and external walls.

If you are knocking down a load-bearing wall you’ll need to replace it with another type of support. The most common is a rolled steel joist or as it’s better known an RSJ. You can ask your structural engineer about the size and weight you need. He or she will also advise you how you can hide the beam and whether or not you’ll also need supporting columns.

While the beam is being fitted any masonry above needs to be supported temporarily. This is done  with acrow props. They will be removed as soon as the RSJ is properly in place.

If you’re planning to attach the RSJ to a party wall though it’s recommended that you speak to a party wall surveyor who will guide you through the regulations and check that the wall is strong enough for the RSJ. If it isn’t then you will need to add steel columns for support.

Hiding a steel beam isn’t difficult. One way is to place it in the floor structure above. This way you will avoid the beam protruding into the room below, so you avoid downstand. It also allows you to keep or increase available height.

If it’s not possible to use the floorspace above then the beams can be placed below the ceiling. You can then box it in with plasterboard. Unless it’s a kitchen you’re renovating and you like the industrial look. In this case you can leave them on show.

If you do though, the beam will need to be fire proofed by painting it with intumescent paint. If it is exposed and isn’t painted it won’t pass the building regulation inspection. Another solution is to build a new suspended ceiling which will hide the beam and give you a level finish.

When you get a quote from a builder remember to ask about repositioning of radiators and any switches or lights. These should be added to the quote along with the cost of the steel beam. You can order RSJs online from B&S Steel.

Don’t forget you’ll need plastering and decorating completed and then there’s the cost of the architect and the structural engineer to consider. Depending where you live and the size of the wall you’re removing, a straightforward builders quote will probably start at around £1500 which means the whole project with professional costs might be just over the £2,000 mark.

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