It must be the weather, otherwise why would we get these crazy ideas: to take on these mammoth DIY jobs, OK maybe not, but it is the hottest day of the year, and my mates have come around and we are having a few cold beers, with some great music.
So you’ve got the scene, and I think the weather (maybe indirectly) has influenced my decision making, even though I have to admit that the cold beer tastes really good. Cos if it wasn’t sunny I wouldn’t be out in the garden with my mates in the first place. My wife however has a completely different interpretation of that particular decision making moment!
Having said that, my wife has to accept some responsibility, as she did say to our friends how nice it would be if the space that we had on the ground floor was more open plan, rather than separate rooms. Of course my mate the builder (who’s name we won’t mention) proceeds to tell us how easy it is to remove walls, and that it would transform our lives with great open plan space, eventually removing the lower back wall of the house almost completely and replacing it with a panoramic set of bi-fold glass doors, which brings the garden into the house and the house into the garden!
That was it, by the end of the evening, (or the end of the second case of beer!) my mind was made up, I was going to remove all the walls on the ground floor. That is a true account of a real situation that I’ve 
been in and repeated many times. It’s a bit like people knowing you’re a doctor, they can’t help but tell you of their ailments, hoping for a magic cure! I’m like a bit of a DIY doctor, but when it comes to removing walls there are strict rules and guidelines! Most houses whether detached, semi, or terraced are generally a square or oblong box where the floor joists (timber beams that create each floor) stretch from the front to the rear of the property.
This is a considerable distance, and in order to prevent deflection (floor springing) a wall is built across the centre of the box to support each floor all the way up to the roof space where is supports the weight of the roof construction, this is called the “spine wall” of the house. This wall carries a considerable load, hence its called a “load bearing wall”!
Removing any section of this wall is a major transformation to the building, but in terms of building skills, requires quite basic construction skills! Lets stick with our story to remove the ground floor spine wall; first job – completely remove furniture, carpets, curtains. You will need: 6/8 acrow props, 4/6 scaffold boards (depending on size of house) and two more acrow props to jack up the steel, for this job.
3/4 acrow props are required for each side of the spine wall, spaced equi-distant with a scaffold board under and over the acrows (on floor and against ceiling) to pick up the weight load of the spine wall. With the acrows plumb and tightened up, the wall is ready to come down. The general rule of thumb for easy and safe demolition is to reverse the build process, so start at the top of the wall, and once the first course or two is removed, the rest comes apart easy. The only tools required are a 2lb club hammer, and a 3inch bolster chisel.
Tommy tip: chisel off all the plaster both sides before demolishing the wall!
If your house is detached, you can cut a hole outside for the RSJ to go through, but in a semi, or a terrace house, you will be cutting into the party wall or walls of your neighbours, and will require a party wall agreement!
In a terrace house, extra brickwork from the party walls will have to be removed in order to install the RSJ, as it will be a minimum of 10 inches wider than the room, and you can generally only cut into the party walls 4.5 inches (width of a brick) you’ll need to get your friends around to help lift the RSJ into place (very heavy). Jack the RSJ up tight and level under the floor joists using the spare two acrow props.
The brickwork under each end of the RSJ should be carefully cut out one course deep, 3 courses high and five bricks long. Fix a plywood shutter over the brick cut out and pour concrete into the void tamping to consolidate, inserting two 12mm steel reinforcing bars the length of the void to create a concrete padstone under the RSJ that spreads the weight load over a large area of the party wall. Leave for a day or two to cure, remove all the acrows, box in the RSJ with plaster board, and make good walls with plaster, and hey presto job done!
Job Duration: First long weekend with a couple of good friends, demolition and RSJ installation. Second long weekend making good and cleaning up
Cost: RSJ approximately £200 -£400
Equipment hire approximately £200
Concrete and making good material approximately £100
Rubbish clearance one skip £250
Total job cost £750-£1,000
These costs do not include any professional fees, and you must carry out any building works in conjunction with the local authority Building Inspector.