Unless you’re enjoying a nice, hot bath, water is usually not your friend when it comes to preserving the life of your home’s surfaces.

Whether it’s just a touch of damp to more serious leaks or flooding, water can do major damage to painted or wallpapered surfaces. The good news is there are things you can do to prevent damp causing problems, and mitigate the damage caused by leaks.

Here are some tips from the Resene advice team.

Prevention is best

When it comes to stopping damp damaging your painted or wallpapered surfaces it all starts with correct preparation.

After you have stripped back any old wallpaper and sanded back any previous paint, do a thorough check of the room for any signs of damp or leaks on the walls, floor and ceilings.

Ashleigh Strange from Resene’s Advice Team says these may include yellow or brown discolouration on surfaces, patches that are colder to touch, crumbling plaster, peeling paint, lifting wallpaper, or spores of black mould that can resemble dirt or pinkish mould often found in bathrooms.

Your next step is to find the source of the leak and repair it so you’re not just repainting over the problem. Check all possible sources of water, such as pipes, tanks, cylinders and guttering, not just rain. You may also need to replace any sections of plasterboard that have become wet.

Ashleigh says it is vital to start at the source and fix any dampness or moisture before painting, or redecorating because mould can and will continue to grow through any new paint system. This is true for exterior surfaces as well as interiors.

“Hydrostatic pressure from moisture is powerful and has the strength to push any coatings off the surface,” Ashleigh says. “It is common to fix one area of concern only for the moisture to make a new channel and make its way out in a new spot.” Resene HydraBlock can be applied to concrete areas where there is hydrostatic pressure and can help to control rising damp and efflorescence.

If you have visible mould or mildew on your surfaces give them a good clean to wash off any loose flaked paint and treat the area with one part Resene Moss & Mould Killer diluted in five parts water. Leave the product for 48 hours then thoroughly clean again before leaving to fully dry. Once dry, you can proceed with applying a good primer like Resene Sureseal and then topcoat.

“Treating and killing mould is a must, rather than just wiping it away or water blasting. By the time the naked eye can see mould it has already taken hold and it does need to be killed.”

As well as coming from leaks, mould can be caused by excess moisture in the air inside your house. You’ll often see it as condensation on the windows on a cool morning. This moisture can come from a range of things like cooking, drying laundry inside, showering without an extractor fan and simply breathing.

Good ventilation is your best friend to combat moisture inside, Ashleigh says. Open windows where you can to move moisture around and out, or use a dehumidifier to reduce moisture levels.

Flood repair

For more serious water damage stemming from major leaks, such as a broken pipe or flood damage, it’s important to allow your home to fully dry out before undertaking any redecorating.

It might be tempting to get things repainted as soon as possible, Ashleigh says, but starting too soon can also cause future problems like mould or timber decay.

In cases of more serious flooding, it’s also important to remember floodwaters can be contaminated so please seek advice from local officials on how and when to proceed.

Once you have the all-clear, the best place to start on the exterior is with a deep clean using Resene Paint Prep and Housewash. Be sure to remove any mud or silt from wall cavities and leave the house to dry thoroughly.

Scrape or sand away any flaking paint and repair any cracks. Once the repaired areas have been sanded, you can proceed with priming then topcoating the walls.

Clean flat surfaces such as concrete driveways or timber decks with Resene Moss & Mould Killer. Wash down concrete surfaces with Resene Paint Prep and Housewash and use Resene Timber and Deck Wash for the deck, followed by your choice of colour in Resene Woodsman stain or Resene Woodsman Decking Oil Stain, or for a lightly oiled look use Resene Furniture and Decking Oil.

If you have interior flood damage, you’ll need to check your plasterboard, skirtings and architraves. They may need to be replaced. It will be easier to assess the full extent of damage once everything is fully dry.

Clean painted surfaces in need of repair thoroughly to remove dirt, debris and marks. It’s also a good idea to clean those surfaces with Resene Moss & Mould to prevent later growth of mildew or mould.

Remove any flaking paint using a scraper and fill all cracks with either sealant or plaster depending on the size of the cracks. Sand glossy surfaces to provide a grip for the paint finish.

From there apply a primer or sealer over the entire area to be painted and apply two coats of your chosen Resene topcoat colour.

Top tip:  Consider asking your local Resene ColorShop staff to add Resene MoulDefender added to your Resene topcoat to further inhibit future moss and mould growth.

July 16, 2023

Resene Paint Experts can help you with specific advice with your project. Simply take photos into your local Resene ColorShop or use the free online Ask a Resene Paint Expert service.

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