Need an extra bedroom, en-suite bathroom or home office? Creating this by putting up a stud wall is a much easier and cheaper option than moving house.
A stud wall comprises a frame of timber or metal studs secured to the floor, ceiling and walls, which is then covered with plasterboard. When you've decorated your new wall, it'll look like an integral part of your house. Building one is a fairly straightforward job, but there are some things you'll need to think about before you start.
First, you should check with your local authority to make sure the work involved conforms to the current building regulations relating to fire resistance, light and ventilation. Then you'll need to organise the lighting, heating and possibly plumbing for your new room. Lastly, if the new wall is going to have a doorway, you'll have to buy a door and frame that matches the thickness of the timber and plasterboard you're using.
You can make a stud wall frame from of either 75mm x 50mm or 100mm x 50mm of sawn timber. This comprises four things. There's a ceiling or head plate, which is fixed to the ceiling joists. There's also a matching length nailed to the floor, called the floor or sole plate. Plus, you'll find studs that stand vertically between the plates, equally spaced and fixed with nails. And lastly there are noggings - short, horizontal braces that give extra support and keep the frame rigid.
You can enjoy better sound and heat insulation by fitting slab insulation between the studs before applying plasterboard to the second side. To stop your electric cables from overheating, it's a wise move to run them inside PVC conduit clipped to the studs or noggings, and pass them through notches rather than holes.
You can get metal frame stud partitions as a kit, including floor and ceiling fixings. They're quicker to assemble and create less mess than timber.
Stud walls are not load-bearing, so you can make a doorway or opening exactly where, and in whatever shape, you want. Although it's a good idea to put a door hard up against one end stud (as this braces the frame more securely), it's up to you whether you do it. Think about how you're going to use your new room, and where you want to put your furniture.
Start by deciding where to put your wall and use an electronic detector to find any joists, cables and pipes in the walls, ceiling and floor. If you want your new wall to run at right angles to the floor and ceiling joists, you can fix it at any point. Or if you'd prefer it to run parallel with the joists, it has to stand directly over one of them. (If you need to install your partition wall between joists, lift the floorboards below and above, and secure 100mm x 50mm timbers at right angles between two joists at 1m intervals to support your new wall.) You'll need to measure from both ends of a wall in the room, and then mark the position for one edge of the stud wall on the floor or skirting board.
Hang a plumb line to the mark you've made. Then, following the plumb line, draw a line up the wall to the ceiling.
Mark the ceiling line using off-cut of wood.
Bang a nail into the ceiling close to the wall junction, at what will become the side edge of the ceiling plate. Then measure and mark the opposite ceiling/wall junction, and make a guideline to show the ceiling plate position by drawing a chalk line between the two points. Use the detector again to find the joists if they're at right angles to the new wall, you'll need to do this to attach the ceiling plate to them.
If you can't find where the joists are by using a detector, try probing the ceiling along the length of the chalk line with a bradawl. The holes you make will be hidden by the ceiling plate. Mark the positions for the fixing points on the ceiling next to the chalk line.
Measure and cut the length of timber for the ceiling plate - it has to fit exactly between the walls at the ceiling. Then hold the plate in place and mark the fixing points along its length. If your wall runs directly underneath a parallel joist, these should be at 400mm intervals. Take the ceiling plate off the ceiling and drill clearance holes for the screws at the marked points. Next, fix the plate in position along the edge of the chalk line using 100mm countersunk cross-head wood screws (nails might crack the ceiling plaster). It's best if you have someone to lend a hand, but failing that, use a wooden prop to help you hold the ceiling plate in place.
Measure and cut the timber for the floor plate, which will fit between the opposite walls (or skirting). If you're fitting a door, find the width of the opening you need by laying the pre-assembled door frame on the floor against the plate. Mark and cut the floor plate so the frame fits the gap exactly, and nail the floor plate to the floor at intervals of about 400mm. If the joists run at right-angles to the wall, follow the line of their fixings (or use the detector to find them) to drive nails into them. If the floor is solid, you'll need to drill holes with a masonry bit and use plugs and screws.
Measure the distance between the ceiling and floor plates at each end of the frame and cut two studs to length (these end studs should be a tight fit). Put each one alongside the guideline you've drawn down the wall and mark the clearance you need for the skirting board. Then use a tenon saw to shape a notch to fit around the skirting board.
Drill clearance holes for the screws along the length of the end studs and mark the positions of the holes on the walls. The first fixings should be about 100mm up from the floor (just above the skirting-board) and 100mm down from the ceiling. The last fixings should be between 410mm and 450mm apart. Drill the marked points on the walls, fit wall plugs and then finish the job off by re-positioning and screwing home the two end studs.
When you're ready to fill in your frame with timber studs and noggings, mark the floor plate at intervals to show where the vertical studs are (they should be 600mm apart). If you need a doorway, start measuring at the wall and work towards where you want the frame. The doorway will be better braced by an adjacent vertical stud.
Use the pre-assembled door frame to measure the width of the header stud that will run horizontally across the top of your door. Cut and nail in place the vertical stud to which the door frame will be fixed. Next, lightly nail the doorframe in place, checking it's vertical with a spirit level and packing out with off-cuts of wood or hardboard, if necessary. Mark the position of the door frame header stud, remove the frame and fit the header stud. After this, strengthen your doorway by fixing a short vertical stud centrally between the door header stud and the ceiling plate, using skewed nails. Nail the frame securely in place.
It's much easier to fix the vertical studs if you nail a supporting offcut block of timber to one side of each vertical stud guideline on the floor plate.
Measure and cut your vertical studs, holding them steady at the base against the block supports. Then fix them to the floor plate with 100mm nails skewed at an angle from both sides of the stud. You can attach them to the ceiling plate in the same way, using a spirit level to make sure each one is vertical.
To reinforce the vertical studs, take a measurement at the ceiling plate and cut short lengths of timber (noggings) to fit horizontally between them. Fit these noggings about half-way between the floor and ceiling, staggering their positions, so nails can be driven straight through the studs into the ends of the noggings. If you're using a metal box to mount a socket outlet or switch, fit an extra nogging to support it or use a cavity socket box instead. You'll also need to fit noggings if you want to mount a heavy item like a washbasin, toilet, radiator or kitchen cupboard on the wall.
Make sure you position all electric cables and plumbing pipes before you enclose the wall with plasterboard. Also, remember to mark the pipe and cable runs on the outside of the plasterboard on one side.
Remember, never take risks with electrical safety. All new or modified installations must comply with the latest IEE Wiring Regulations, and new or replacement cables or sockets may require RCD protection. If you're planning to make changes to a power or lighting circuit in your bathroom, firstly, you must inform your local authority's Building Control Department.
First, plan the runs of your plumbing pipes by marking the faces of the studs with a tenon saw. Carve out the pipe runs with the saw or a chisel and mallet. It's a good idea to make the notches slope backwards very slightly so they'll hold the pipes while they're fitted. If you need a deep notch (for a waste pipe, for example) reinforce the stud with a bridging piece.
Drill holes for cable through the middle of the noggings. Make sure you leave enough room for a generous air gap around the cable to prevent overheating. And remember not to run electric cables and plumbing pipes through the same holes.
When you've put your stud wall framework in place, you'll need to cover it with 12.5mm-thick plasterboard. This comes in different widths, lengths and types - including acoustic check plasterboard that gives you better sound insulation. Tapered-edge boards make it easier to get a smooth finish using tape and jointing compound.
Standard plasterboard has a grey side and an ivory side (which faces outwards). You'll need to cut the sheets to fit, especially if your walls and ceilings aren't completely straight. As your knife blade will become blunt very quickly, it's worth using a knife with replaceable blades for this job. And if you're cutting a lot of plasterboard, specialist plasterboard blades will be quicker, safer and give you a cleaner cut.
Vertical or horizontal? You can fix plasterboard sheets horizontally or vertically (which is easier, as they're heavy and can rest on the floor). If you're fixing your sheets vertically, position each width so that the joins align at the centre of a stud. If you're doing so horizontally, you should nail the bottom row of boards to the frame and stagger the vertical joints. But whichever way you choose, you'll need to start at the doorway and work outwards at either side. Using handy boards (plaster lath sheets)
Worried that you'll have trouble carrying or handling full-size plasterboard sheets? You'll find 1220mm x 600mm handy boards are easier to manage. But as these are smaller, they need a lot more fixings, which means the job takes longer and you end up with a patchwork finish. Also, think twice before trying to finish handy boards with tape and jointing compound as it's difficult to achieve a smooth surface. You'll be better off getting a good plasterer to finish the job with a full plaster coat.
Start by measuring the sheets to 12mm less than the floor-to-ceiling height. Mark the cutting line on the ivory side of the plasterboard, then cut along it using a craft knife and straightedge.
Turn the plasterboard over and fold the end along, then cut to snap the board. Use a craft knife to cut through the paper backing.
Get someone to help you attach the plasterboard to the frame - it's much easier with two people. A wood off-cut used as a 'floor lifter' will help you raise each board tight up against the ceiling as you fix it. Make sure you fit the plasterboard with the ivory side outwards, and finish the joints with tape and jointing.
Starting at the door studs, carefully position a full-size board vertically and ivory-side outwards to cover half the width of the door stud and half of one other stud. Then wedge a bolster chisel at the foot of the board, slide a wood off-cut underneath and use your foot to press down and force the board hard up against the ceiling.
Fix the board in place with 32mm plasterboard nails at roughly 150mm intervals, 15mm away from the edges. Carry on fitting whole boards in the same way as before, cutting them to fit above the doorway and against the adjacent walls. If you also have a skirting-board, you'll need to notch the plasterboard to fit around it.