Diagnosing water damaged ceilings should be an easy thing to do even for an untrained eye. Depending on the ceiling covering, look for a discoloring of the paintwork. If the ceiling has been papered, watch out for paper starting to peel away, quite probably while also discoloring. Although this could be due to factors other than water damage you’re best advised to at least investigate what’s causing the problem, to avert things from getting worse.
Under extreme circumstances, where there is a buildup of water above the ceiling, water damage can immediately cause a hole to appear in the ceiling, so no fear of not detecting that. However, following on from an initial discoloring or paper peeling, a further sign to look for is the appearance of rings on the ceiling where water has crept into the ceiling and then dried, leaving a ‘tide mark’. Concentric rings would indicate the slow accumulation of water on the ceiling, if not dealt with in time this could cause water to drip down eventually causing a hole in the ceiling.
What you Need
Presuming the water damage has only affected part of the ceiling there’s no need to replace the whole ceiling. Instead, dependant on the extent of the damage, you can carry out a repair to the damaged ceiling with a piece of drywall, some plaster and scrim, timber and few basic tools.
If the water damage is only slight, having fixed the cause of the water damage, you might only need to re-paint and/or re-plaster the ceiling. If the water damage has left a patch of the ceiling plaster loose and friable then gently chisel out the damaged plaster and then re-plaster the damaged area.
If you have a deep section to re-plaster, you might need to insert some plasterer’s scrim to help the new plaster to hold in place. Allow it to dry thoroughly then seal the new plaster with a plaster sealant; you can then re-cover the whole ceiling.
Repairing Holes in Water Damaged Ceilings
To tackle a hole in the ceiling, you’ll need to have access to the joists near the hole from above the ceiling as well as below it. Clear any old/damaged plasterwork back to the nearest joists.
Cut two lengths of 50mm square timber to match the long sides of the hole, adding 25mm to each length. Cut two more 50mm square bearer battens for between the joists you’ve had to clear plaster away to.
Nail the lengths along the length of the hole to the joist, fitting them inside the hole so that about 15mm to 20mm of the old plaster protrudes. The exact amount here will depend on the thickness of the drywall you’re using.
Angle nail the two bearer battens above the lengths and into the joists at the ends of the hole. Using an old chisel, remove a layer of plaster from around the hole, about 25mm wide. Measure and cut the drywall sheet so that it will fit into and onto the timbers you’ve just nailed in, then nail the drywall in place to them.
With a dab of plaster, fix the scrim in place around the layer of plaster you chiseled out then, using a hawk and trowel push plaster over the area to be repaired. After an hour, or when dry, apply a finishing coat and then smooth and polish it with a metal float. When thoroughly dried, in a day or two, it can be re-decorated.