Ready Reference: Plasters and Wall Fillers

WHICH FILLER TO USE

Cellulose filler or ready-mixed filler for:

• superficial cracks in plaster and plasterboard

• small holes (up to 50mm/2in) across

• gouge marks in plaster

• joint cracks in plasterboard or coving

• filling dents and cracks in wood to be painted.

Finishing plaster or brush-on skim plaster for:

• large holes (over 50mm/2in) across

• deep cracks in plaster

• patches where unsound plaster has been stripped off

• skim coats on plasterboard.

Wood stopper in matching shade for:

• wood to be given a natural finish.

Flexible mastic or ready-mixed filler for

• gaps between woodwork and walls (round windows and door frames).

 

TOOLS FOR MAKING GOOD

• a filling knife with a 25-50mm (1-2in) wide blade. This has a more flexible blade than a wallpaper stripping knife, and is useful for small repairs

• a hawk for holding plaster close to the work (something you can make yourself from a square of plywood 450 x 450mm with a piece of thick dowelling for the handle)

• a plasterer’s trowel (also called a steel float) used for applying plaster and polishing the surface

• an angle trowel is also useful for making neat right-angled internal corners

 

WHICH FILLER IS WHICH?

Cellulose Fillers

Cellulose fillers are based on plaster with added cellulose resins to improve flexibility, adhesion and reduce drying time.

• remains workable for up to 1 hour

• it will shrink, so cracks should be overfilled and sanded back

• expensive to use in large quantities

• dries white.

Ready-Mixed Fillers

Ready-mixed fillers are like ordinary cellulose fillers, but with added ingredients to improve performance and sold in plastic tubs.

• quick-drying in thin layers (thick layers may take up to 24 hours)

• less likely to shrink or slump

• waterproof, so can be used in wet areas or outdoors

• relatively expensive to use in large quantities.

Plaster

This is made from gypsum (calcium sulphate) and numerous different types are available.

• for most repair jobs, Sirapite or similar finishing plaster is ideal

• available in bags from 5kg (11lb) upwards

• relatively inexpensive for large repairs

• very quick setting (less than 30mins)

• may shrink in deep cracks or thick layers

• dries grey or pink.

Brush-On Skim Plaster

Brush-on skim plaster, specially-formulated and ready-mixed, is designed to be brushed on and smoothed with a spreader instead of a float.

• remains workable for up to 4 hours

• doesn’t shrink or crack

• more expensive than plain plaster

• dries white.

Wood Stoppers

Wood stoppers are resin-based ready-mixed fillers designed for wood that’s going to be varnished.

• sets quickly with little shrinkage

• dries wood-colour but can take stain.

Flexible Mastics

Flexible mastics are rubber or acrylic-basic sealants designed for gaps between walls and woodwork where sight movement would crack ordinary fillers.

• remains flexible without shrinking

• can be painted

• available in different colours.

08. August 2011 by admin
Categories: DIY Home, Internal Repairs, Plastering, Walls | Tags: , , , , | Comments Off on Ready Reference: Plasters and Wall Fillers

Follow

Get every new post delivered to your Inbox

Join other followers: