Drywall Screws

They fix plasterboard sheets to metal profiles or to timber battens in walls and suspended ceilings. The bugle head sinks into the board without breaking the paper facing, and the thread holds the board firmly to its support. They are screws designed for this use and must not be replaced with timber or metal screws.

It depends on the type of screw: there are self-drilling plasterboard screws that bore their own way through metal profiles, while standard timber screws or plasterboard screws for timber are not suitable for metal. For thin profiles a self-drilling screw with a point suited to the thickness is preferable. Always check on the product sheet whether it is indicated for the profile you are using.

Fine thread is more suitable for thin metal profiles, as it goes in with less effort and holds the material well. Coarse thread is indicated for plasterboard fixed to timber, because it grips the timber support better. As for length, the screw must go through the board and penetrate the support by at least a few millimetres.

Collated screws are driven with a screwdriver with an automatic magazine and are designed for large surfaces, because they save time and effort. Loose phosphated black screws are used for hand fixing, small jobs or hard-to-reach areas. For large sites collated screws are more practical, while loose screws are for touch-ups and details.

The distance between screws depends on the thickness of the board and on the type of system, and is given by the manufacturer in the installation instructions. In general the screws are inserted at a regular distance from the edge and from one another, without creating rows so close together that they weaken the board. Consult the technical sheet of the system for the correct distances.

Set the screwdriver to a suitable torque and stop when the screw head is just below the surface of the board. If the screw sinks too far the paper tears and the fixing loses strength; if it stands proud, the fixing is not correct. Use a bit of the right size and check the depth from time to time.

The screw must be longer than the thickness of the board, by enough to penetrate the support. For thin boards and metal profiles short screws are needed; for double boards or thicker timber supports, longer screws. The diameter and length are indicated in the product code, so read it carefully before buying.

For assembling metal profiles, screws with a washer head or a self-drilling point are needed, suitable for fixing the profiles to each other or to the structure. The washer head spreads the pressure better and reduces the risk of the profile deforming. The choice depends on the thickness of the profile and on the type of wall support.