How To Repair Blistered Paint

April 3, 2015 August 31, 2021 past

Updated on August 31st, 2021

I was raised in several colonial and Victorian era homes on the New England coast and, from the moment my male parent start taught me how to paint our house, my summers consisted of more than hours behind a castor than I care to recollect.

Every bit anyone who has scraped, sanded, primed and painted a house knows, there is no feeling more than frustrating than watching your hard work peel off prematurely the following summertime.

During my dwelling house inspections, I regularly see older homes that appear to take been painted recently but seem to be suffering from a premature blistering paint problem, which some people describe as paint bubbles. Sometimes you lot can even poke one of the blisters with a knife and water volition ooze out of the pocket — an alarming moment to a prospective homebuyer.

Blistering Paint on Exterior Wall

When I see this, I similar to ask my clients what they retrieve is happening. Some of the answers I hear frequently are: The siding was not properly scraped and primed, the seller was using inexpensive pigment or they painted in the pelting without assuasive the building to properly dry. While all of these causes are plausible, at that place is a more probable reason that frequently goes overlooked. To understand, let'south call back about the difference between onetime houses and new houses.

Why is This Happening?

For the purposes of this article, an old firm is any firm built prior to our current energy codes – think late 1960s and earlier. These homes are not as airtight every bit newer homes, and so there is by and large more than air moving through the walls. This is both good and bad. The drawbacks are heat loss and higher energy bills. The upside is that air moving through the walls helps keep the building dry. This is one of the things that makes older homes less susceptible than modern homes to rot and wood decay.

Blistering Paint

When you come across blistering paint on the outside of an onetime house, at that place is a pretty skillful chance y'all are witnessing the effects of heat loss – air moving through the wall, carrying moisture in the form of vapor. This does non usually hurt your edifice but does create expensive and frustrating ongoing painting costs.

Is This a New Miracle?

In the former days, this was seldom a problem, for a couple of reasons. Start, we used to pigment our buildings with oil-based pigment, which does non trap wet as finer equally latex paint. Too, they used to fasten siding to homes using nails with rounded heads – back when siding was hand-nailed and not practical with a pneumatic blast gun. These sometime nailheads created a slight gap between boards – a identify where moisture could escape. Today, older homes have many layers of paint and the bottom edges of the siding are sealed by successive layers of latex. The result is that at that place is no place for wet from the within to escape, so it bubbles off the finish paint in blisters.

How Can I Fix It?

On the outside of the business firm, cut open the paint on the bottom edge of the lap siding with a razor knife to let air escape. Ideally, you practise this right after painting, but if your pigment task has already blistered, you will need to too scrape, prime and repaint the failed areas. If the lap siding is still very tight, y'all can try inserting forest shims to pry open up the siding and allow a identify for moist air to escape. Y'all usually do not need to do this everywhere, just where the siding is blistering.

Inside the house, be mindful of relative humidity: Attempt and continue the interior air dry using kitchen fans and bath fans to vent wet outside. Aim for an indoor relative humidity beneath 55 percent in the cold conditions months; the relative humidity can be measured with a temperature and humidity meter. If indoor relative humidity is too high, run your bathroom fans more frequently

More extensive air seal-up can also help. This will make the domicile more energy efficient as you deadening heat loss through the house. This may include sealing up gaps in walls and floors to foreclose air migration into the walls. This kind of work is typically done as office of an energy efficiency retrofit; local contractors who do this work tin can be constitute nether energy audits or "home operation."

I promise this helps explain an unusual phenomenon we often see when looking at houses. Call up: Cognition is power when looking at homes. Savour your business firm hunting.

About Dylan Chalk
Dylan Chalk is the owner of Seattle-based Orca Inspection Services LLC – www.orcainspect.com. He is likewise the founder of ScribeWare software, offering innovative and uncomplicated report writing solutions. He can be reached at dylan@orcainspect.com. Or come across his blog at http://getscribeware.com/blog.

Note: This is a guest mail service; the views and opinions expressed are those of the author and do not necessarily reflect the stance or position of Redfin.