Painting Tips for Newfoundland & Labrador

Paint is one of the most important lines of defence for wooden clapboard, trim, mouldings, windows, and doors. Yet the climate of Newfoundland and Labrador is very challenging when it comes to keeping paint on a wooden building. High winds and wet conditions allow water to seep into the tiniest crevice and, once wood gets wet, paint gradually loses its adherence. Selecting the right approach to applying paint is critical to ensuring that it performs well. The old methods of applying clapboard and paint were based on generations of observation of what worked. The fact that we inhabit our homes differently today than in the past has an impact on how well paint will adhere to the outer wood cladding and how well the old methods might perform.

In the past wooden buildings were rarely insulated, which meant that the air could circulate through the cavity wall and dry things out. The result was often a generally drafty building. Today most people insulate their older buildings to make them tighter, to cut down on heating costs, and to enhance comfort. Today’s homes tend to generate more internal moisture, through cooking and showering, that can seep through walls. And whether a property is used largely for seasonal or year-round use will have an impact on the amount of internal moisture generated. These all have implications for the way paint performs.

One of the biggest questions remains, “Do I use latex paint or oil paint?” Older generations of builders often suggest that oil is superior. But, for environmental reasons, oil paint is increasingly difficult to get. Latex is seen as more convenient because it dries faster (shortening the time for application), is more ecologically friendly, and allows for the easy cleaning of brushes and rollers. So what is a building owner to do? In this section we attempt to lay out some of the different approaches and provide information on the pros and cons of each. Heritage NL does not assume responsibility for any of the recommendations contained in this document as performance of clapboard and paint will depend on a wide range of factors such as how a building is performing and the conditions under which paint is applied.

 
 

The Case for Latex Paint

The Guide to the Installation of Exterior Cladding on Heritage NL’s website advocates for the use of latex paint applied to clapboard and wood trims that have had a “rainscreen” or second line of defence installed. A rainscreen employs a protective wrapping over the building’s sheathing, onto which ¾ inch wood strapping is applied to act as a nailing surface for the clapboard. This creates a space between the clapboard and a building’s sheathing, which permits air to circulate, allowing the clapboard to dry out. This approach is recommended if latex paint or stain is to be used, as they will not repel water in the same way as oil paint and will require drying.

If an old wooden building is to be insulated, it is strongly recommended that it be done on the exterior of the outside wall cavity with a rigid insulation. This leaves the wall cavity space open to allow air to circulate and keep wooden structural members dry. If sealing up an old building it may be necessary to install an HVAC system to mechanically ventilate it, particularly if a continuous moisture barrier cannot be installed – which can only be done if a building is being gutted. Excessive moisture in a building will make it difficult to keep paint on its exterior.

When strapping is installed at greater than 12 inch intervals, there is a larger space between nails on the clapboard. This can cause the clapboard to buckle, causing aesthetic issues and openings that allow moisture to enter.

An alternative to wood strapping is the use of a rolled rainscreen, which is a plastic ribbed, highly porous material that can be stapled directly to the outside sheathing of a building. Clapboard is nailed through it directly to the outside sheathing providing an airspace. It comes in different thicknesses and has the advantage of a thinner profile than wood strapping and therefore doesn’t require the removal and strapping out of existing window, door, and corner trims.

The Guide also recommends the use of “spunbonded olefin protective membranes” (of which “Tyvek” Building Wrap is a common product name) to be used underneath the strapping. This provides a rainscreen under the clapboard but is supposed to allow moisture to move through from the inside. There are examples, however, of the disintegration of the spunbonded olefin membrane underneath clapboard that has been applied without strapping, perhaps as a result of a reaction to direct contact with wood.

Traditionally, tar paper or “felt” was used to wrap wooden buildings. When properly applied, it seems to offer very good protection for the wood sheathing underneath. There are lots of examples of wood sheathing under felt being in good condition even though the clapboard or trim boards may have rotted considerably. A heavy grade tar paper can form effective water-proofing underneath wood cladding. A traditional practice was to install a small square of felt underneath any joints in new clapboard to provide added protection when the joint, invariably, opened up.

 
 

The Case for Oil Paint

Advantages of oil paint include its greater bonding to wood than latex – which is fast-drying and sits on the surface of clapboard, windows, and trim – and its great ability to repel moisture. Oil paints, if thinned with mineral spirits, have the ability to soak into wood as they slowly dry. Traditional building wisdom is to apply it in fairly cool conditions to slow down drying even more. One informant, who built wood windows for many years, indicated that his family operation used kerosene to thin down paint as a primer coat on windows and clapboard. In more recent years it has been recommended that new clapboard be primed on the back side as well to keep out moisture.

The fact that petroleum-derived oil paints are increasingly unavailable due to environmental concerns means that simply getting oil paint can be a challenge. Marine paints are still available in oil and can be used on buildings but they are only available in a limited range of colours.

An alternative may be the use of linseed oil paint,  which is environmentally friendly and possesses the adherence and preservative qualities of oil paints. At one time linseed oil paint was the norm in Newfoundland and Labrador, outside of the use of marine animal oils in paint. Linseed oil paint is more expensive than other paints but one can get more coverage out of a can and it is said that, with proper care, it can last 20 years or longer. Prior to applying linseed oil paint one applies as much linseed oil as the raw wood will soak up. This serves as a good wood preservative. Linseed oil paint can be applied to wood that has had its old paint removed. With additional coatings of linseed oil every few years, this finish can look good for many years and will never require scraping. One supplier is the Swedish company Allback, which has a Canadian supplier.  For more information see:  https://sagerestoration.com

Pictured from top to bottom: Twillingate; Harbour Grace; St. Julien’s; Summerville; Elliston; Makkovik.

 

Additional Painting Tips

  1. Regular Maintenance – Regular maintenance of paint finishes will help to preserve the wood underneath. If a paint finish is allowed to deteriorate significantly before repainting, moisture can get into exterior wood cladding and hasten rot. Scraping and painting on a regular schedule can ensure a longer life for both paint and wood. One approach, often used in the past, is to paint one side of a wooden building every year, ensuring that every 4 years the entire house gets repainted or touched up. This includes caulking cracks as soon as they develop, particularly where clapboard meets trim boards.
  1. Ensure your wood is dry – Traditional practice was often to repaint a building in late summer (after the fishing season) to give it ample time for the wood to dry out. Paint adheres much better to dry wood than damp. Spring or early summer is likely not the best time to paint as there can still be considerable damp in the wood. The exception to this can be shop-painted new clapboard (see below) which can be installed in virtually any season, although a final coat should wait until warm, dry weather.
  1. Sand between old and new coats – When applying a new coat of paint over an old one it is best to do a light sanding with fairly coarse sandpaper first as this will roughen up the finish and improve bonding of the new paint to the old.
  1. Use primer – After scraping your building, use a good quality primer on bare wood surfaces as this will improve the adhesion of new paint. For new buildings prime all of the wood before painting. To allow the new coat of paint to cover better, mix some of your tinted paint in with the primer so that there is less contrast with the new coat. If you are putting latex paint over an old oil paint surface, it is critical that you use a primer, ideally an oil primer over which both oil and latex paints can be applied.
  1. Paint new clapboard in a shop – If you can, it is best to paint new clapboard in a dry, controlled environment and to allow proper drying time between coats. There are various pre-painted shop-finished clapboard products available. They are likely to provide the most durable paint finish compared to one painted on site. Newfoundland Wood Siding Company is a local supplier: http://www.nlwoodsidingco.ca
  1. Hire a reputable painter – If you are not doing your own painting, hire a reputable company to do it for you. A professional will ensure that your building is properly scraped, rotten wood is repaired, and new caulking installed prior to painting. Budget painters may be tempted to cover over problem areas leaving them to create bigger problems down the road.
  1. Take care using paint on masonry – Exterior brick, concrete, and stone is sometimes painted to spruce up discoloured or deteriorating surfaces. While it will make your building look brighter, over time it can do great damage to your exterior masonry surfaces. Paint acts as a sealant that doesn’t allow moisture trapped inside to be expelled. There is often an assumption that masonry finishes are impervious to water. This is not the case as most bricks and stones are porous. And if moisture gets trapped behind paint, it will start to break apart the masonry through our rapid and frequent freeze-thaw cycles, not to mention causing paint to flake off in fairly short order. Latex/acrylic paints are often recommended for masonry but these are not deemed to be ideal. Mineral-based paint or stain will give the desired protection, breathability, and durability and is environmentally safe. This will likely be a special order so best to check online or talk to your local paint distributor.
  2. Authentic Interior Wall Finishes – For a more authentic historic look for interior painted wall finishes, consider using a brush rather than a roller. Or use a wide brush to go over the last wet coat of roller-applied paint. The effect is rather different than the pebbled finish that results from a roller. You may even consider adding glazes of a different colour over a base coat to evoke paint finishes of the 19th century.
  3. Stripping Old Coats of Paint – Especially on interior trims and mouldings it is sometimes desirable to strip off the built-up layers of paint that obscure fine detailing and profiles. Great care should be taken in stripping old paint as paints from the first half of the 20th century and earlier generally contained lead. While lead is considered a toxic substance, old lead paint needn’t be a problem if it is: a) left intact and painted over or; b) stripped in an appropriate manner. Due to the high level of heat generated, traditional heat guns allow for the lead to off gas, which can be hazardous if inhaled. As well it is easy to scorch wood with them. Proper masks are critical. Chemical stripping can be used as well but tends to be slow and produces chemical waste. A recommended strategy is to use an “Infrared Stripper” which is safer in that it doesn’t allow lead to be off gassed due to its relatively low temperature. Appropriate masks should still be used. Old stripped paint should be properly dealt with as a hazardous waste.
  4. Get advice – If you have any questions or special problem situations with paint finishes get in contact with Heritage NL. We can share the experience of numerous historic properties, agencies, and experts. If we don’t know the answer we will do our best to find one.