It’s that time again – that glorious transition to spring weather when we find ourselves spending way too much money at Home Depot, deciding on the year’s heirloom tomato lineup, realizing all the nooks and crannies of the house that desperately need a power wash, and bitching about the bare spots in the lawn.
Summer’s coming.
Transitioning from fine furniture to outdoor furniture has some distinct differences that woodworkers should be aware of. This post will serve as a beginner’s guide to building pieces for outdoor spaces, helping makers and homeowners see what considerations are necessary for quality and enduring outdoor furniture.
I feel qualified to talk about this because I have built pieces in the past that mother nature absolutely destroyed. No better way to learn than from complete failure, right?
The right materials, construction methods, and an outdoor-minded design all need to be considered to build quality furniture that stands up to the unforgiving elements.
GET INSIDE MOTHER NATURE’S HEAD
Bottom line up front: no outdoor furniture will last forever without periodic maintenance/refinishing. The best designs will effectively stave off the damage. Here’s what outdoor furniture needs to stave off that indoor furniture doesn’t:
-Large temperature and humidity swings
-UV exposure
-Rain and snow
-Insects
Your designs need to mitigate these factors to the maximum extent possible.
Rain
If the design allows for rain to pool in a certain area, that part of the piece will degrade faster than the rest. Care should be taken to maximize the ability for water to flow away or through members of the piece so stagnant water can’t collect.
If you’re designing an outdoor table and determining whether to make a slatted top with small gaps in between the boards or a solid, laminated top – all else being equal, the slatted top will “weather the storm” better.
Question to pose: “Does the water have a place to escape?” If the answer is no, it may be worth reconsidering the design.
Bugs
A lot of insects like wood. Specifically, they like holes in wood. This can occur most commonly with fastener holes. Countersunk screws, and pocket hole screws can leave holes that will entice bugs if they aren’t plugged. Ensuring that you apply finish in the holes can mitigate wood damage, but it’s not going to stop them from setting up shop in your fastener holes.
Question to pose: “Does my design provide vacancy for critters?” If so, consider wood plugs or an outdoor-rated wood filler.
Temperature/Humidity
Temperature and humidity affect wood furniture in a couple ways, but the main effect is cyclical expanding and contracting of the wood fibers which can loosen joints over time (at best), or break joints apart (at worst). You can get extremely nerdy here – understanding the specific wood species and seasonal equilibrium moisture content percentage changes based on the local area – but that’s not entirely necessary.
Here’s a good rule of thumb to keep you from making dumb mistakes: If a board is 4 inches or wider, make sure it has room to breathe or joinery that allows for expansion across the board width.
UV Exposure
UV exposure from the sun is a huge contributor to wood wear and deterioration, but design doesn’t have a huge role in alleviating UV damage. We’ll save that for the next section on materials.
CHOOSE THE RIGHT MATERIALS
Just to be clear, this section is about ALL materials used to build furniture: wood, adhesives, fasteners and wood finish. All these components work together to help give a piece lasting strength and beauty.
Wood Selection
All wood species are not created equal. Yes, outdoor finishes can be applied to extend the life of a sup-par wood but it’s more effective to just start with exterior-rated woods.
Wood species that hold up well outdoors have inherent structural and chemical properties that make them resistant to rot and decay, both from weather and insects.
Some common domestic woods include cedar and white oak. Cedar is light, soft, and very easy to work with. It’ll make a fine tabletop as long as dents aren’t an issue. White oak is quite hard, heavy, but still relatively easy to work with. The woodworker should be cautioned when building with white oak because of the resultant weight of the piece. This is crucial if the piece is to be portable/moved around frequently.
There are several exotic hardwoods that are praised for their weather resistance, including teak, ipe, garapa, and cumaru. These tropical woods are very dense and very heaving. This makes them great for applications such as decking or tabletops as they can take a lot of abuse. These woods also come with a very high price tag, so they may be prohibitive to the weekend woodworker experimenting with outdoor furniture.
Wood Finish
After you’ve selected a wood species, you want to determine how you will finish it. Below are the main categories of wood finish, and their benefits and drawbacks.
-No finish: Choose a rot resistant wood and let it decay naturally. A good solution if you don’t mind a nice grey or silvery weathered look and appreciate almost zero maintenance.
-Oil Finish: Different formulations of natural oils (and sometimes hardeners) that penetrate and protect the wood from within. Oil finishes give a nice, natural feel to the finished piece but will need to be reapplied periodically to maintain protection.
-Film finish: Different formulations such as urethane or lacquer that build a film thickness on top of the wood. This is more effective at blocking UV rays and keeping out moisture but if the finish does wear (it will eventually), it’s a lot more work to repair. Film finishes often need to be stripped, sanded, and reapplied, vs. oil finishes which can just be lightly sanded and re-oiled.
-Paint: Arguably the best outdoor finish in terms of protection and longevity. The tint of the paint provides better UV protection than clear film finishes while also keeping moisture out of the wood. Paint may not fit your intended look, but it helps to know why it’s so effective.
Fasteners
For outdoor fasteners, choose something that’s either corrosion resistant stainless steel (CRES) or something that has a proprietary coating for outdoor applications (the fasteners will likely be colored). You can choose to conceal fasteners either by using matching wood plugs (in the case of pocket holes or counterbored holes for screws), or if you like the aesthetic of clean stainless steel screw heads, then leave them on display.
Adhesives
For adhesive, your best bet is to go with Titebond 3. This is a water-based PVA glue (polyvinyl acetate) that has water-resistant properties (unlike Titebond 1 or 2). There are other adhesives you could use, but this is a beginner’s guide, so this is a great place to start and will meet the needs of most projects.
Starting with weather appropriate materials is crucial to the overall quality and endurance of an outdoor piece. It also helps to understand the final location of the piece you’re building. Will it be on a covered porch protected from the harsh mid-day sun or pounding rain? Or will it be out in the open yard taking the full brunt of sun rays and rain? This can help give you an idea of what finishes you can get away with, and whether you should consider covering the piece to protect it from weather or storing it indoors when not in use.
Every homeowner has a different appetite for maintenance, so it behooves you to create your own personalized strategy that you can sustain without unnecessary frustration.
OTHER PRO TIPS
Here are some additional tips and tricks for outdoor furniture, in no particular order.
-To protect furniture legs from absorbing excess moisture, create “epoxy feet”. Flip the piece upside down and create a well on each foot with masking tape. Then pour a shallow coating of 5-minute epoxy (approx. 1/8”). The epoxy will completely seal the end grain fibers of the feet keeping excess moisture out.
-When it comes to wood finish, more tint = more UV protection, meaning clear finishes will do a less effective job at resisting UV damage than pigmented finishes. If you want a natural wood look, just know that periodic maintenance on the finish will be required.
-Use glue and fasteners - a belt and suspenders approach. The adhesive will make the joints more rigid, but the fasteners will keep the joints from separating if the adhesive were to fail in the future.
-Don’t get crazy with sanding grits. Check your wood finish instructions to see what is recommended. Remember, mother nature will take its toll and weather the piece no matter how smooth you sand it. Anything above 180 grit for outdoor furniture is unnecessary. For film finishes or paint, 120 grit is sufficient.
PARTING GIFTS
For woodworkers whose bread and butter is fine indoor furniture, you might feel the need to achieve the same level of precision with outdoor furniture.
I don’t see it the same way.
For me, the primary considerations with outdoor furniture are strength, weather resistance, and overall aesthetic. What takes a backseat is precision – I just don’t think its as necessary. To be clear, when I say precision, I mean minor aesthetic imperfections that don’t negatively impact the strength of the piece.
It’s also very freeing, because when you don’t have a requirement for absolute precision, you feel more confident experimenting with different forms – things like interesting geometric patterns, or non-rectilinear shapes. The creativity flows better because you’re not shackled by the need for perfection.
It can be amazing how dialing back standards in one area can help to boost your creativity and ultimately improve your craft.
Frame the project differently, and paths for growth start to reveal themselves.
Thanks for reading! If you have specific questions on outdoor furniture or are interested in commissioning a piece, shoot me an email at longoluccowoodworks2020@gmail.com, or head over to the custom inquiry page to contact me!