What Is Shiplap Siding?

Shiplap siding is a type of wooden siding made from board planks. It gets its name from the fact that the specific construction technique has been used for centuries to build different kinds of boats, perhaps even from the time of the Vikings in Scandinavia.

Shiplap siding differs from board and batten siding and other types of wooden siding alternatives, mainly by preparing each wooden plank or board used. Each wooden plank or board has a groove cut alongside the board during the prep process, which allows each plank to overlap slightly with the next one. The overlapping effect from one piece to the next essentially seals the siding. It makes for a solid wall face without any creases where air or moisture can enter. In contrast, board and batten siding covers the space between each plank with a separate piece of wood. With shiplap, the overlapping design of the siding allows for a smooth exterior or interior as each part fits neatly together. Most shiplap siding is designed to be installed horizontally. However, it is possible to cut the tongue and groove cuts vertically as well.

When shiplap siding is cut and installed correctly, the tongue and groove interlocking system creates a seal that protects against wind, rain, and moisture. Space where the wood connects also allows the wood to naturally expand and contract with the seasons and as the wood ages. 

This characteristic means that the lumber on your interior or exterior siding will be less susceptible to buckling and cracking. Some types of wood siding will shrink or crack over time, thus potentially allowing jeopardizing the building envelope of your home. On the other hand, Shiplap siding is generally better suited to enable the wood to settle naturally over time. This way, the energy efficiency and thermal performance of your home are not compromised.

What Does Shiplap Siding Look Like? 

All shiplap siding for both home interiors and exteriors will rely on some tongue and groove cut to connect or "fit together" the different wood pieces. However, this doesn't mean that all shiplap siding will look the same. You can choose to install shiplap siding horizontally or vertically. However, horizontal is much more common and will be more accessible at local hardware stores and lumberyards. The way you finish the shiplap siding will also impact the final appearance. For example, a neat coat of glossy white paint (zero-VOC, of course) will allow for a clean and modernist finish. Painting shiplap siding with a natural-colored varnish (check out this Rise guide to healthy wood finishes for your home) will offer a more rustic, natural feel.

What Is the Best Wood To Use for Shiplap Siding?

In theory, you could make shiplap siding from any number of different types of lumber. In many cases, you might be able to find salvaged wood from old barns or century homes that are being torn down. Often, older homes utilize exclusive hardwood lumber that is exceptionally resistant to the elements and can last for centuries when proper care is taken. A local carpenter or lumber yard can repurpose some wooden planks from an old barn and even pre-cut the tongue and groove fits.

If you can't find salvaged wood and don't want to spend a fortune on fresh hardwood lumber, cedar is generally the best option. Cedar planks are more moisture-resistant than pine. They also naturally resist termites and other pests much better than pine. Suppose you plan to use shiplap siding as an exterior siding that receives driving rain or bathrooms, kitchens, or other interior spaces where moisture might be an issue. In that case, cedar is the way to go. Otherwise, cheaper pine lumber is a good option for most other spaces.

How To Seal Shiplap Siding?

As with all wood siding, furniture, and any other wooden material, properly sealing and finishing the wood is necessary to improve its durability and moisture resistance. If you are purchasing unfinished wood planks for your shiplap siding, adding a clear coat sealer to the boards will give them an additional layer of moisture protection. Most pre-painted shiplap boards that you purchase from hardware or home improvement stores will already have this layer of sealant.

However, it might be a good idea to add extra sealant along exposed edges and seams. These locations are where driving rain and excess moisture can cause damage. If you like the natural look of wood, varnishes add an extra layer of protection against the elements.

How Long Does Shiplap Siding Last?

The durability of shiplap siding will depend on several factors. These factors include the type of lumber you use, correct installation practices, properly sealing and finishing the wood, regular maintenance, and even your home's orientation. In general, however, shiplap siding should last for anywhere between 20 and 30 years, if not more. Solid oak planks that you repurposed from an old barn, for example, could easily last for another 100 years or more as an interior or exterior siding for your home. On the other hand, cheaper commercial pine boards will be much more prone to shrinkage and moisture damage. One leading company called Shiplap Direct offers a 20-year warranty on all of their exterior shiplap siding products.

Where To Buy Shiplap Siding?

Most major hardware and home improvement stores will have a vast selection of shiplap siding. Some online retailers specialize solely in shiplap siding for home interiors and exteriors. To name just one example, Shiplap Direct has a considerable inventory of shiplap siding, including premium primed shiplap, raw pine shiplap, cedar shiplap, exterior siding shiplap, and even a unique line of custom shiplap products.

Centennial Woods, based in Wyoming, specializes in reclaimed wood siding if you prefer to opt for repurposed, recycled, or salvaged wood. Also, consider checking Craigslist or your local Classified Ads. Also, Habitat for Humanity's ReStore specializes in selling pre-loved building materials. You might be able to find some gems of old, hardwood planks for very low prices. You can also find salvaged wood planks and boards at local demolition sites.

Major home improvement stores are also taking notice of the growing interest in reclaimed or salvaged wood. Home Depot, for example, is currently selling kiln-dried genuine reclaimed barn wood planks.