Catering for Drain Pipes

Filed Under: Do it yourself, Home repair, Plumbing, Remodeling    by: ITC

An important consideration when building an extension is the position of any drainage pipe run — either an existing one from the house or any new waste pipes from fittings in the new extension. You must sort out the route the pipes will take before the walls are built since they will pass through them below floor level, and openings must be left in the walls as they are built.

Lintels will need to be incorporated to support the wall above the openings. If the extension is to have trench-fill foundations, ducts should be made in the concrete to allow the passage of pipes. A simple method is to set slightly larger pipes in the concrete as it is poured and then run the pipes through these round openings later.

The positions of the inner and outer leaves of the walls should be marked centrally on the concrete of the foundations with chalk. The center lines of the wall and foundations being within lin of each other.

As the walls are built, stringlines are stretched between the corners to make sure each course of bricks or blocks is laid in a straight line.

Although you can use brick for both inner and outer leaves of the wall, in practice it makes more sense to use lightweight concrete blocks for the former since these will provide a certain amount of insulation — a requirement of the Building Regulations.

With this type of construction, the inner leaf is the load-bearing part of the wall, carrying the weight of any floors and ceilings so lintels must be fitted across doorways and windows. Steel boot lintels are best since they are relatively lightweight and their shape ensures that any water that penetrates the outer leaf of the wall is prevented from reaching the inner leaf and is channeled out over the toe of the boot.

The two leaves of the wall should be constructed simultaneously, laying a few courses of each at a time. As construction proceeds, the two leaves must be linked together with metal or plastic wall ties to prevent them leaning away from each other.

Ties are designed to prevent water running across them to the inner leaf but they must still be set in the mortar joints so that they slope downwards slightly towards the outer leaf. Ties should be set about 18in apart vertically and 3ft apart horizontally, the positions in each horizontal row being staggered with those above and below. At door and window openings, ties should be set one above the other at 12in intervals.

Water penetration must also be prevented from below and this is achieved by inserting a flexible bitumen damp-proof course (DPC) in a horizontal mortar joint around the base of each leaf, at least two courses of bricks above ground level.

When the floor is laid, a damp-proof membrane (DPM) is taken up the walls and tucked under the DPC. Strips of DPC must be fitted in the vertical mortar joints where the inner leaf is turned to close off the cavity at windows and door openings, and below the threshold of the door, linking to the DPC in the outer leaf.

The walls must be toothed into the existing house walls at alternate courses to ensure permanent stability.

Building a Stud Partition

Filed Under: Do it yourself, Home repair, Remodeling    by: ITC

The easiest form of partition to build is the wood frame variety — it is ideal for dividing one bedroom into two, making an extra powder room or bathroom, or splitting a dining area from a kitchen or living room. The wood frame is simply nailed together and faced with drywall on each side; it is easily adapted for doorways, pass through or windows. Being essentially hollow, it can also be used to conceal electrical wiring and water pipes.

The framework comprises a number of uprights called “studs” fitted between lengths of wood spanning the width of the ceiling and floor. These are called the “head plate” and “sole plate” respectively. Short horizontal lengths of wood are fixed between the uprights to brace them and support the cladding. In most cases 2 x 3in rough sawn softwood is ideal for the studs and bracing, with 11/2 x 3in for the head and sole plates. If the partition is to carry a lot of weight such as shelves or cupboards, a larger size should be used, say 2 x 4in.

Planning the partition

Deciding where to put the partition is the first thing to do so that you end up with two usable rooms. If possible arrange things so that each new room gets the benefit of a window, but do not be tempted to set the partition so that it divides a window in two. Not only does this look dreadful, but in some cases it is also illegal. If you cannot provide a window for each room, glaze the upper portion of the partition so that you can “borrow” some natural light from the room with the window. Similarly, if you cannot provide an opening window for each new room, you will be required to install a form of mechanical ventilation.

Important considerations are the layouts of floor and ceiling joists since the head and sole plates will be attached to these. Ideally, the partition should run at right angles to the joists so that its weight is spread across them. If this is not possible, it must be directly above a joist. With a solid floor, there is no problem.

If the head plate does not span the ceiling joists and does not come below a single joist because the ceiling joists do not line up with the floor joists, you should nail lengths of 2in sq blocking between the ceiling joists and attach the head plate to these.

Before you begin work, check under the floor and above the ceiling for any cables or pipes that might be damaged by nails or screws. It is also a good idea to check with your local Building Code before carrying out any structural work.

Erecting the framework by cutting the head and sole plates to length; whenever possible buy wood long enough so that you can span the room with one piece. Nail the sole plate to the joists through the floorboards using 4in long common nails or fix it to a concrete floor with 4in long No.10 woodscrews and wall plugs or with masonry anchors or masonry nails. Screw the head plate to the ceiling joists.

Cut the studs for each end of the partition, leaving them a fraction over-length so that they will be a tight fit between the head and sole plates, and screw them to the wall. Use 4in long No.10 screw and wall plugs.

Then mark off the positions of the other studs along the sole plate, making sure their centers are 16in or no more than 24in apart. They should be positioned so that the edges of the cladding material will meet along their center lines (standard sheets of drywall are 4ft wide). If the partition is to have a door in it, the stud positions on each side of the opening must be adjusted to allow for the door width and the thickness of the lining.

Measure and cut each stud individually as there is no guarantee that head and sole plates will be parallel.

Set each stud in place, making sure it is vertical with a spirit level, and fix it by driving 3 or 4in common nails at an angle through the side of the stud into the head and sole plate (known as toe-nails).