How To Repair Cracks In Ceilings, Fibacryl

Over the years I have experimented with various products in an attempt to permanently repair cracks in ceilings. Today I share with you my secrets on “How To Repair Cracks In Ceilings” permanently.

Why Does My Ceiling Have Cracks?

There are several reasons why your ceiling may be cracking.

1) The wooden ceiling joists that plasterboard are attached to expand and contract. This movement causes cracks mostly at the location of the plasterboard joints.

2) New homes are plagued with shrinkage cracks due to the wood used in construction shrinking causing settlement cracks. Cracks in newly built houses can appear not only on the ceilings but walls to. Every house will go through a settlement phase, after a few years, the cracks once repaired should not reappear.

3) Poor construction, in most cases plasterboard sheets are secured to the ceiling joists using cheap clout nails. Unfortunately nails are not as effective at limiting the amount of movement (expansion, contraction) as Plasterboard Screws.

There are nails available called, Passivated Clout Nails which have threaded rings around the shaft. These type of nails have a similar effect to screws, increasing holding power.

How To Repair Cracks In Ceilings

The first step to successfully repairing a ceiling crack is to understand that filler alone will only temporarily repair, disguise the crack. If the crack has appeared due to movement, then it will reappear.

How then do you permanently fix cracks in ceilings? The answer, Toupret Fibacryl Flexible Repair Filler. Using a filler that naturally moves with the ceiling is the key.

Below I have detailed the steps on how to repair cracks in ceilings.

Step 1

Use either a Stanley Knife or a Painters Multi Tool to open the crack. I realise that it may seem absurd to purposely make the crack worse, but without enough width and depth, the flexible filler has nothing to adhere to. When opening the crack try to create a V, wider at the surface and narrow at the deepest point.

bahco stanley and purdy multi tool

Step 2

Take your Toupret Fibacryl Cartridge and using your stanley knife cut a 45 degree angle at the nozzle. Next insert the cartridge into a Painters Caulking Gun and squeeze the filler into the crack.

Step 3

Using a damp cloth dampen your finger and run it over the fibacryl pushing it into the crack. Leave enough room 1-2 mm for the final step (skimming).

NOTE : Wait 30 mins – 1 hour before moving onto step 4

Step 4

Take your Toupret Interior Filler and Flexible Mixing Bowl and mix up some interior filler. Using a Flex Filling Knife skim over the crack and wait until dry. Mix up more toupret filler and skim the crack again, wait until dry and move onto the last step.

I find it beneficial to work with a 6 Inch Flex Knife and 3 Inch Flex Knife. Once the filler is mixed, transfer onto the larger flex knife and use the smaller 3 inch one to work with.

After you have filled the remaining 1-2mm with toupret interior filler, remember to run your flex knife over the crack to remove any excess filler. This means that when you come to your second fill, you do not need to sand the area.

toupret filler, flexible mixing bowl, flex knife

Step 5

Sand the filler using 120 Grade Sandpaper attached to a Hand Sander until the filler is flush with the surface. The ceiling is now ready for painting, you do not need to prime or mist coat toupret interior filler as it does not flash.

how to repair cracks in ceilings

Toupret Fibacryl can be used on (Gypsum plaster, Plasterboards, Painted or Unpainted surfaces, Concrete, Cement, Breeze blocks, Bricks, Stones, Primed woods, Mortar).

Available in 350ml cartridges, 1kg, 5kg tubs, further information can be found on the product data sheet below.

Fibacryl Flexible Filler Alternative

I should mention that there is another product that can be used to fix cracks in ceiling. CT1 Multi Purpose Sealant Adhesive, bonds to: (metals, glass, wood, plasterboard, brick), does not shrink, can be painted and is also flexible.

What I love about CT1 is that it can be used for a variety of applications interior and exterior, I have used it for 1) Filling large gaps between skirting boards and walls prior to painting 2) Fixing architrave and skirting to walls 3) Repairing cracks in ceilings 4) Waterproofing PVC window frames.

how to repair cracks in ceilings

CT1 comes in a variety of colours (anthracite, beige, black, brown, grey, oak, silver, white) 

Either products will provide a permanent solution to fixing cracks in ceilings. If you do choose CT1 Adhesive instead of Toupret Fibacryl, ensure that you follow the steps above as the process to repair cracks is the same for both flexible fillers. Further information the uses for CT1 can be found on the product data sheet link below.

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