Home Sweet Home

The project is to install a skylight in a concrete tile roof to provide a lightwell for maximum lighting in an enclosed kitchen. The skylight will be 800 mm square so will need a rafter cut, and the lightwell is to be painted white for maximum natural light.

Step by Step

1 The size of a skylight is based on the floor area of the area to be lit. It is generally recommended that the skylight be at least 10 per cent of the floor area. In this case the skylight will be 800 mm x 800 mm.

2 Order the skylight, specifying size, roof type, the shape required, and if any accessories, such as diffusers or solar control features are required.

3 Climb into the roof space to decide where the skylight is to go.

4 Remove tiles and sarking felt in the area where the skylight is to be installed. Treat the tiles carefully as some will be needed later. Stack them to one side.

5 Carefully mark on the rafters and battens where the skylight is to go. Make a 50 mm allowance top and bottom of the rafter for the trimmers which are needed to frame the cut-out hole. This should be done with reference to the ceiling and where the lightwell is to go. Also take note of any wires, pipes, roof ridges or valleys that may affect the installation, or will require moving.

6 Cut the battens flush with the rafters, and nail any loose trimmed battens to the rafters. Make sure no battens run across the area in which the skylight is to be installed.

7 There is a bend in the tray of the skylight and this should be in line with the bottom edge of the batten.

8 As this is a wide model, it will be necessary to saw through one rafter at the top and bottom of the cut-out. Do this carefully to the marks, making sure you have made an allowance for the thickness of the trimmer top and bottom.

9 Cut two trimmers to length, top and bottom, to secure the cut rafter. The trimmer should be a tight fit between the two adjacent rafters. Measure the trimmer directly. When nailing it in place ensure that it is completely square to the rafter and truly horizontal using a level. A short length of rafter will be needed between the trimmers to allow for the width of the skylight.

10 Remove the internal catches that hold the dome of the skylight to its base. In most cases these will be internal toggle catches.

11 Place the base over the opening. Make sure that the joint where the flashing joins onto the base is supported by a tile.

12 Secure the anchoring straps of the base to rafters by nails or screws.

13 Make sure that all the folds and channels on the base have not been deformed as this could affect the waterproofing of the skylight, especially in high winds.

14 Re-lay the tiles to within 50 mm of the vertical side upstands of the base. (To do this with terracotta tiles it may be necessary to remove the lugs from the underside of the tiles.)

15 Dress the lead flashing over the lower tiles. In high- exposure areas, point up with cement mortar between the lead and tiles. This should not, however, normally be necessary.

16 As we are also fitting a lightwell it may be easier to leave the dome until the lightwell is installed. Usually the dome would be fitted into position as recommended by the manufacturer and the toggles replaced and firmly sealed from the inside.

17 The lightwell can be flared to be wider at the ceiling than at the skylight. This will give a better distribution of light in the room. However, keep the lightwell between the matching ceiling joists and expand it in the other direction, otherwise large trimming joists will be needed to support the ceiling adequately — especially if the ceiling is a large one.

18 Measure down to the ceiling where it is to be cut. Mark on the ceiling rafters the position of the lightwell. Drive a nail through the ceiling lining to mark each corner of the lightwell on the underside of the ceiling where the cuts are to be made.

19 Make sure that there are no electric wires, telephone wires or plumbing pipes in the lightwell area before cutting.

20 Mark out the rectangle to be cut on the ceiling on the room side.

21 Cut the ceiling lining to the marks with a panel saw. As it is plaster it should be easy to cut but, if working from below, wear goggles and a face mask to protect the eyes and breathing passages against plaster dust.

22 Install the trimming joists for the ceiling, once again making sure that the opening is framed square.

23 The simplest method of lightwell construction, where the distance between roof rafter and ceiling joist is not great, is to make the well out of chipboard or medium density fibreboard. This is carefully marked out to the shape required, and prefabricated using adhesive and nailing, before being fitted.

24 The lightwell is then lifted into place from the underside of the ceiling, and nailed in place.

25 Finish the lightwell with a timber trim to cover the joint to the ceiling.

26 As an alternative, the lightwell can be framed between the roof rafters and the ceiling joists. This is best made of 75 mm x 38 mm softwood framing. The job will be greatly simplified with the use of nail plates to enable you to build the box on top of the ceiling joists, and directly under the roof rafters. You will, however, find that due to the construction of the roof they will be offset by the thickness of a roof rafter. Remember to design the framing with corners so that you have something to fix the lining of the lightwell to. When the frame is secure the lightwell can be lined. It is best to use a `warm’ material as this will have greater resistance to condensation. Timber linings are excellent, but foil-backed plasterboard, particle (chip) board or plywood would also suffice. A high level of finish is not required to the lightwell if it is hidden behind a diffuser. However, if there is no diffuser, greater care will be needed in finishing off.

27 Finish the interior of the lightwell with two or three coats of white vinyl paint.

28 A diffuser panel can be loosely fitted on top of neat timber battens nailed to the sides of the lightwell, flush to 50 mm from the ceiling level. These should be installed prepainted.

29 Fit the diffuser by passing it up at an angle and twisting it and lowering it into position.

Possibly related posts: (automatically generated)
Installing a Skylight

• Let in the Light, Bright ideas for Light and Shade
• Increasing and decreasing daylight
• Add Flair and Style to Your Home with Structural or Ornamental Beams
• Care for Windows, Curtains and Blinds
• Decorate Beautiful Eye Catch Point: Windows part 4
• Handyman Rules for Roofing
• Window Dressing (Fabric)
• Interior Lighting Design, bring Lights into Your House
• Decorate Beautiful Eye Catch Point: Windows part 1
• Skillful use of color continue...