Filling Small Cracks in Wall

- Filling small cracks in wall
- Filling odd gaps and holes in the wall
- Types of fillers

Small cavities, cracks, holes or gashes in plaster walls or ceiling can be repaired with interior filler. If you think that this job might be too big for you we advice you call a builder or handyman.

1. Scrape out the crack with a filling knife. If the crack is in plaster board and the paper surface has been torn, cut off jagged edges with a sharp trimming knife. Run your knife along the crack pointing into the wall first to the left then to the right. This will create an inverted V shape which, when filled, will hold itself in place far better.
2. Brush the crack in wall with a dry brush to remove dust.
3. Mix filler into an easily workable paste. This should not be sloppy. Using an old cup or similar container is far easier than mixing on a flat surface. Pour in a little powder and add water whilst stirring to create a smooth paste. Alternatively, take the easy route and use a filler that is ready mixed to fill the crack in wall. To save yourself a lot of sanding down and time, follow the technique below rather than the common one of over-filling to allow for shrinkage, and sanding back smooth
4. Load filler onto the end of the filling knife blade and draw the blade across the crack. Scrap the excess of the blade, ten draw it down the crack to remove excess filler from the wall and smooth the surface.
5. For deeper cracks in wall which are more like larger holes, build up the surface in layers, working from the edges. Wait about two hours for each layer to dry before putting the next layer onto the hole in the wall.
6. After you have filled the crack in wall and the filler is completely dry, smooth it to the level of the surrounding surface with medium or fine abrasive paper wrapped round a wooden block, or use a power sander with fine-grade sandpaper so that the crack in wall will no longer be visible and the wall will be smooth. You can now paint if necessary.

Advice & Tips
When filling a crack in wall, if the filler draws away from the wall as you smother it with you filling knife, try wetting the blade.

Filling odd gaps and holes in wall or ceiling

Sometimes there are holes in wall that just can’t be filled correctly with standard interior fillers. You can buy special fillers to deal with them
Odd gaps and holes will include the long cracks in wall running from the top to the bottom of a wall–especially in stairwells. These can be filled, but if they open up again, this could be an indication of a structural problem. It is advisable that you contact your local builder or surveyor for some advice.
Cracks often occur a t wall joints or wall and ceiling joints and between wall and woodwork. All these can be filled with a flexible mastic.

Foam Filler

Deep cavities–around a pipe through a wall, for example–can be difficult to fill but the job is easier if you use foam filler. Wear the gloves supplied–the foam is very sticky until it sets.

Before you start-experiment to see how fast the foam comes out of the nozzle and how much it expands.

1. Brush any dust out of the hole and dampen the surface with water
2. Allowing for expansion, realease foam into the hole. You may only need a thin bead.
3. Leave the foam for 1 to 2 hrs. When it has set, cut any excess away with a hacksaw blad or a sharp knife. Weear a mask to avoid inhaling the dust.

Flexible Mastic
Gaps between walls and window frames, skirting boards, door frames and staircases, move. Therefore they should be filled with a flexible mastic that sticks well and resists craking. The mastic is applied with a cartridge gun.

- If the craxks are deep, half–fill them with tin strips of expanded polystyrene before applying the sealant
- Make sure the sealant readhces bothe sides of the gap. Press it in ansmothe rthe surcae with a wetted fingertip.

Helpful Tip
Instead of licking your fingertips to un alona bead of sealant, dip it in a solution of 50:50 water and washing–up liquid. If you has sensitive skin, use the back of a wetted teaspoon instead.

Tools: Old paintbrush; filling knife; abrasive paper and clock, or power sander. Possibly also: trimming knife: Large paintbrush;colde shisel; garden spray gun; length of wood
Materials: Suitable filler