Learn to Build – Building the Walls
Building the Main Walls
You now have the luxury of a level working surface because as soon as the B.I. has passed the work to date, you can fill in the gap between the footings and the excavated ground.
This is the time to lay your roll of plastic DPC.
I know that your wall tops will be perfectly level and smooth but, it still doesn’t stop you running a thin bed of compo to help hold the DPC in place before commencing to lay the bricks or stones.
The DPC will extend over the outside and inside edges of the blocks by at least 25mm 1″ or more.
This can be trimmed later when the build is complete.
As before when you commenced the start of the footings, start at the corners.
This is probably elementary after having built the footings but, I have to write it or someone will say that I didn’t explain it clearly enough.
Measure out where your doorway is going to be.
It must be at least 370mm 15″ from a corner, and you don’t want a small part brick next to the doorway.
Lay down the bricks dry without compo first allowing a 10mm space between them.
This space between bricks is called a ‘perp’ short for perpendicular. After measuring out your first course, remember to start inserting the stainless steel ties, first ones onto the DPC.
This is very important as the insulation bats (usually 1200mm X 450mm 4′ X 18″)will rest on these.
The next row of ties go on top of these bats and so on all the way up the wall.
Try to start your doorway with a full brick at both sides on the first course and then a half brick on the second course, and so on.
When you reach the height of the wall where there is a window as well as the doorway measure the bricks carefully so that no perps fall above another perp.
If necessary, trim the length of 1 or 2 bricks to ensure a half lap over the lower perp.
The closer one perp is to the one beneath, the weaker the wall.
Starting almost immediately above the DPC, you must consider how you are going to tie-in your new walls to the existing house wall.
You have the option of cutting out holes all the way up the wall and building your new bricks/ blocks, into these holes, or you might choose the favourite modern method of using ‘Crocodiles.
These are 1200mm long pieces of pressed out steel with slits in.
These come supplied with fixing screws and plugs. They are fixed by drilling several holes into the house wall and secured with the screws.
Place one crocodile directly above the centre of each wall (inner & outer).
With each crocodile comes several clips around 150mm long, that clip into the slots in the affixed uprights. They rest on top of each course of brickwork, and are cemented in. Repeat this all the way up the wall.
Working to your drawings or the plans in your head decide whether you are going to build in a solid window sill or have uPVC sill supplied by your window manufacturer.
This is probably the most popular with new builds but, it may not fit in with the rest of your house or the adjoining properties.
Note that the sill must protrude around 50mm 2″ out from the wall to allow water to drain away.
The old brick built houses often used bricks laid on their sides side by side tilted up slightly at the back inner wall end to cause a water run off, away from the window frame when it was fixed in place.
In other cases it was more common to use a pre-formed reinforced concrete sill. These have a sloping front edge and a drip groove running lengthways along the front lower edge. In stone buildings these are exactly the same but, carved from solid stone.
Continuing the Upward Build
The most important part of the upward build is to ensure your corners are square and more importantly plumb….that is to say perfectly perpendicular.
Because all upward building is always started from the corners, it is absolutely imperative that these are spot on.
This is where your long spirit level comes into its own. For speed of build, many professional house builders erect wooden corner uprights.
This not only speeds up the build but, also saves the company a lot of money in labour man hour costs, so perhaps it’s seriously worth considering.
I confess that I have used this method on several builds.
It’s simple. Take 2 long (say 4 metres 13′) 100mm X 25mm (4″ X 1″) pieces of sawn timber and lay them together, one laid flat and one on its side to form a long ‘L’ and nail or screw them together.
These can now be stood upright at the corners to build into.
Before standing them upright, hammer a couple of stout wooden stakes well into the ground about 1200mm 4′ away from the corner in line with the run of the new walls.
These are used to secure the corner uprights in place.
Use pieces of the same size wood to secure the corner uprights in place.
Get someone to help you, use your spirit level to make sure that it is perfectly, I repeat perfectly, upright before one of you screw it securely in place.
Use more wooden stakes if necessary, it must not move throughout the build.
Repeat this at both outside corners. It may seem a bit faffy and could take you a couple of hours but, it could save you days in correcting and constantly checking your work.
I would go even further and say that it is almost essential if building with uneven chiselled stone.
When it comes to using any timber, try always to save money by buying reclaimed timber or check on ‘e-bay’ before wasting your money.
I know from personal experience that sheet materials such as plywood, MDF, chipboard, or OSB Stirling board, can be a fraction of what the timber yards charge.
So, you have built up your walls and provided openings for door and windows.
You have correctly measured the heights of your door and window frames and reached the height where you must install the lintels.
There are several different types of these.
Like the sills, some are reinforced concrete, others are stone effect, or real stone.
Despite which type you choose,all these will need a reinforced concrete one for the inner wall.
You must provide a DPC tray above the outer wall to catch any condensation or weepage that may run down the inside of the outer wall.
At each end of the lintels, you must build into the perps, small weep holes, available from your builders merchant.
Different types of steel lintels are also available, most common are the Catnic range.
The most popular ones span the cavity and support both the outer and inner walls together and don’t require a DPC tray but, still need the weep holes.
These have a thin lip to the front and rear and therefore can have the bricks or stones laid straight onto them.
For the old cottage effect, the bricks or stones can be laid side by side stood on end (Soldier bond). Remember, all the lintels up to 1200mm must extend both ends at least 100mm 4″ and if longer than 1200mm 150mm 6″ on to your newly built upright walls.
This rule applies to your soldiers as well for best effect.
After installation of the lintels, you can continue as before on the outer walls but, on the inside you must consider what type of first floor suspension you are going to use.