Water Behind Paint on Plaster Cladding

We recently carried out an inspection for a client who started to notice patchy discolouration on their cladding. Naturally concerned, they decided to get a thermal imaging scan carried out.

Fortunately for the home owner they had a cavity system in place so the likelihood that water got across the cavity, then across the building paper which is wrapped around the framing was very remote. The moisture meter did not detect any sign of moisture on the framing at the time of inspection.

Take a look at this photo…

Look closely and you can see in the righthand image where the paint has changed colour, and in the lefthand image the infrared camera is dark in colour which indicates a change in temperature.

What’s going on here?

To start with, the home had not been painted with an elastomeric paint since built. Plaster houses should be painted by an approved applicator every 5 – 7 yrs. The reason you need an approved painter is so your paint manufactures warranty will be valid (The good painters warranty the work). EG. If Joe the painter down the road puts the wrong paint on top of the existing paint, then it could bubble up after a couple of years, especially on the sunny side of the house. You need someone who stands by their work and doesn’t run for the hills when you call with a workmanship issue.

In the above image, the resins in the paint have literally broken down and the water has soaked through the paint and into the cladding system… and therefore the paint can no longer adhere to the cladding. Even if your paint looks fine, it can ‘all of a sudden’ take a turn for the worse if you don’t maintain it. If there was no cavity behind this cladding, it could have really turned to custard for this home owner because the water would most likely find its way onto the framing.

In this case, the paint may need to be scrapped away from this area to dry out the cladding behind, otherwise if they paint directly over the area where moisture has already penetrated through, it will most likely with fail and discolour again.

Planning to get your home painted?

Get an infrared imaging scan for moisture first, then proceed to contact a certified applicator of paint onto plaster systems. The company you employ should also do the crack repairs and seal around the windows as part of the job.

Although we don’t do this type of repaint work ourselves (We only do the moisture testing and infrared inspections), feel free to call us and we can suggest a couple of experienced companies who specialise in this type of painting at a fair price, and further back their work with paint manufactures warranties in place. These are independent painters who do not form part of our company. Always get multiple quotes.

Buying at Auction Costs & Tips

Are you buying at action?

Sadly, many people get ‘caught out’ at auctions in NZ because they don’t know what to look out for.

It’s almost sickening how many properties we end up moisture testing in NZ for clients who ‘just purchased’ at an auction, only to move into the house and find signs of leaks (most of which were hidden under carpet and behind furniture etc). Most of them ‘thought’ the house looked fine from what they could see… before they purchased the house. In addtion, they thought they got a good deal!! I wonder why?

Basic buying at auction costs and tips:

Is getting a thermal imaging leak inspection a cost, and money I could potentially loose before an auction ? Yes it is… but don’t miss this step! It’s AMAZING how many times clients say to me “We didn’t want to pay for an inspection incase we didn’t win the auction”. Just plain silly thinking don’t you think? Absolutely.

99% of my clients have it written into their property contract to get a building inspection and/or moisture test prior to buying the house, so why wouldn’t you do the same in an auction scenario?

What should you look for prior to buying at auction? (From a leak detective’s point of view)

  • Look for swollen skirting boards
  • Look for discoloured carpet grip in the corners under the carpet. This will most likely mean a leak is coming in from somewhere
  • Look for any visual signs of joinery failures
  • Look for any bubbling of paintwork under windows, on ceiling, in bathrooms and on just about every surface of internal and  external walls
  • Cracks in cladding and around windows
  • Lack of ground clearence
  • Any leaks around plumbing, such as under sinks and in the corners of shower screens.

These tips listed above are only a hand full of what to look for in your initial ‘visual’ inspection. The next step is to get an experienced thermal imaging company to take a look using infrared technology to detect issues you will not see, like these ones… coupled with experience in moisture testing nz houses.

Do not buy at auction until you are 110% sure there are no moisture issues in the house… and we say this with certainty after seeing so many home buyers getting caught out buying lemons. If anything, we can do a verbal inspection for you (no report), which is cheaper and will give you certainty when you buy. If you are happy with the inspection results and win the auction, you can then request a report for a small fee.

Moisture Testing Houses on Dry Summer Days

“Can you moisture test a home on dry summer days? “… a common question clients ask in summer time.

Yes you can, but there’s a couple of things to consider. Before I explain further, here’s a photo of a major leak below a window that we detected on a hot dry Auckland day with thermal imaging and moisture meters… (You can see the mould stain on the internal side of fiber cement board)

The timber doesn't look too damaged does it?
The timber doesn't look too damaged does it?

This is a very common type of window leak that was caused be cracks opening up around where the plaster cladding meets the aluminium window frame. There were no visual signs of this leak on gib board, skirting or external cladding.

So can you detect moisture problems in houses when it hasn’t rained?

First of all, there is a difference between moisture and leaks. Moisture will accumulate in a wall (with no cavity), and penetrate into insulation as a result of a leak. Moisture will stay long term, even if you fix the source of the leak… and if the timber in the area is untreated, mould and decay will start to take place, and you won’t even know it. A pitched roof leak for example could be missed if it hasn’t rained for some time, as the air circulation in the ceiling space will potentially dry the leak out… but not so with trapped moisture in walls.

The moisture damage below the window above was due to lack of cladding maintenance around the windows… coupled with design issues.

Here’s part 2 of what happened with the job above:

The home owner got his local builder to take the gib board off where we had found the leak. The vendor then had the source of the problem fixed and they used a dehumidifier to dry the area out. He kept the area open and dry of two weeks before replacing the gib, plastering and painting. The reason he went ahead and closed it all back up is because the timber frame looked and felt dry… and the screwdriver didn’t go through the timber when he tested further. Then…

He called me back to do a ‘re-test’ and get a clean moisture report. Guess what? After all that time drying it out, the moisture readings came back at 60% (Well over 18 – 20% moisture that it should be). Why was this? The moisture was inside the untreated timber and couldn’t be ‘seen’. See, the window leak was running down the internal side of the cladding where the timber frame was touching, therefore the majority of the water was soaking in through the back on the timber and across… and didn’t leave much visual evidence on the side of the timber that could be viewed.

Now what?

The area is now getting pulled back apart and the timber is coming out. Ideally, he would have had it moisture tested before closing it back up.

Summary: Dehumidifiers won’t completely dry out moist untreated timber, and what ‘looks’ dry may not be… even if you can’t push a screwdriver through it.

Further info about how moisture can accumulate in walls HERE