SHED BUILDING VIDEO 2 OF 15
How to Choose the Best Lumber and Plywood for a Shed
Starting any construction project begins with choosing the best lumber and materials. It pays to carefully hand pick lumber and plywood at the lumberyard.
Taught by Henry Reinders, a professional builder, renovator and woodworker with more than 45 years of hands-on experience.
Popular Video Chapters
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0:04 Understand why material selection matters
Learn why straight, dry and structurally sound lumber is essential for strong, long-lasting shed construction.
0:33 Choose pressure-treated floor framing
Henry explains why pressure-treated 2×6 joists are used when floor framing rests close to gravel, soil or sod.
0:57 Sight every board for bows and twists
See how to sight along both faces of every board and reject bowed, twisted or crooked lumber before purchase.
1:21 Avoid wet lumber and problem knots
Identify dry pressure-treated boards without large knots to reduce warping and weak spots in shed floor framing.
1:53 Select 3/4-inch tongue & groove plywood
See why 3/4-inch tongue & groove plywood provides a strong, stable shed floor for tools and equipment.
2:26 Choose strong exterior-grade plywood
Henry compares fir, pressure-treated and spruce plywood and explains the material choice shown in this project.
2:57 Read grade stamps and follow local codes
Learn how to read plywood face labels, orient matching sheets consistently and follow applicable local building requirements.
3:59 Inspect both plywood faces before buying
Inspect both plywood faces for missing knots and choose the smoother veneer for a durable finished shed floor.
BUILDING THIS SHED?
Free Shed Building Video Tutorials
Complete Plans When You’re Ready
Use the video tutorials to help build the shed. Use the plans for exact dimensions, drawings, material lists, construction sequence and the included Excel costing sheet.
Shed Lumber and Plywood Quick Reference
Material quality decides how easy the rest of the build goes. Here’s what to look for at the yard.
Key specs at a glance
- Floor joists shown: straight, reasonably dry pressure-treated 2×6 lumber
- Floor plywood: 3/4-inch tongue & groove fir, not spruce
- Panel orientation: label-down follows code; label-up sometimes has a better, smoother finished face
- Knots: avoid large or loose knots in structural lumber -weakens the lumber
Common mistakes to avoid
- Checking a board for straightness along only one edge instead of two planes
- Buying pressure-treated lumber that has too much moisture — it warps as it dries
- Using spruce plywood instead of fir when durability and extra strength matters
- Mixing label-up and label-down sheets across the same floor – tongues and sheets won’t line up
- Overlooking a few large knots because the board looks fine otherwise
PROJECT RESOURCES
Need a Budget? Price the Project Before You Build
Download the free Excel costing sheet to enter current local prices, provided for both shed plan sizes and both old and recent Excel formats (just in case you need the older file format).
Frequently Asked Questions
Questions are based on the topics covered in this video and common questions Henry receives from customers via email.
Should shed floor joists be pressure-treated?
Yes. Pressure-treated lumber is recommended for shed floor framing because the joists are positioned close to the ground and may be exposed to moisture. This applies whether your shed is built over gravel, sod or soil. Watch at 0:33
How can I tell whether framing lumber is straight?
Pick up each board and sight down both its edge and face. Check it from more than one direction because a board may appear straight along one plane while being bowed or twisted along another. Take the time to inspect every board at the lumberyard. Straight material makes it much easier to build a floor, walls and roof that are square, level and properly aligned. Watch at 0:57
Should pressure-treated lumber be dry when purchased?
Choose pressure-treated lumber that is reasonably dry and not unusually heavy with moisture. Very wet lumber can twist, bow or warp badly as it dries, particularly when stored outside in direct sunlight. Purchase only as much lumber as you can use within a reasonable period and keep it properly stacked, supported and covered until needed. Watch at 1:21
Why should I avoid lumber with large knots?
Large knots can create weak points in structural lumber. Boards with large knots are also more likely to twist, bow or warp as their moisture content changes. Small, tight knots are generally less concerning, but avoid boards with large, loose or missing knots in floor joists, wall plates, headers, rafters and other structural components. Watch at 1:21
What plywood is recommended for a shed floor?
Three-quarter-inch tongue & groove fir plywood provides a strong, durable shed floor, particularly when heavy equipment such as lawn tractors, rototillers or other machinery will be stored inside. Fir plywood generally has a harder and stronger surface veneer than softer plywood such as spruce. The additional cost of ¾-inch plywood is usually small compared with the added strength and stability it provides. Watch at 1:53
Is pressure-treated plywood required for a shed floor?
Pressure-treated plywood can be used when it is available, but it is not always necessary. Regular fir tongue & groove plywood can provide a strong floor when supported by pressure-treated 2×6 floor joists and protected from prolonged moisture exposure. The correct choice will also depend on your climate, foundation design and local building requirements. Watch at 2:26
Must tongue & groove plywood be installed with the labelled face down?
For construction subject to building codes or manufacturer requirements, follow the specified panel orientation. For the shed shown in this video, the smoother face was installed upward to create a better finished floor. The labelled side had smaller, tighter knots and fewer missing sections than the opposite face. Whichever orientation you choose, install every sheet consistently. Do not install some sheets label-up and others label-down, because differences between the panel faces can produce uneven joints. Watch at 3:59
Complete Video Transcript
Use the expandable transcript to read Henry’s instructions found in this video – with timestamps linked to each section in the video.
Open the complete video transcript
Welcome to country life projects I’m Henry Reinders this is video 2 of 15 videos in our shed project in this video I’m going to cover selecting material for the floor of your shed and the type of material to use however just want to point out doesn’t matter what part of the shed you’re working on it always pays to take your time to select the right material and good material so before you head out to the lumberyard highly recommend you watch this video in this video we’re going to go over a material selection there are some important considerations and we’ll start with the two by sixes they’re pressure treated you definitely want to have pressure treated
because you’re going to be resting these directly on the ground whether you have gravel down for your base where you’re going directly onto sod or soil pressure treated is the way to go what you want to look for when you’re selecting your material is that they’re straight and the way you would do that you just simply pick up this when you’re in the store and you wouldn’t run your eye down here and you would look down here and down this plane if they’re straight both ways you have a nice straight piece of wood you want them all like that also you’ll notice that this isn’t too heavy it’s important when you’re buying pressure-treated lumber try and
buy it so it’s reasonably dry if it’s really wet really heavy it’s impossible to know how they’re going to warp and more than likely they will especially once you get them under your yard they’re sitting in the Sun you know it’s chances are they will work really badly so fairly dry nice and straight critical also avoid any pieces that have any big notch you’ll notice if you look at this lumber here there’s no big knots big knots tend to be weak points they also tend to be places where the lumber will warp more than average now as far as plywood goes go to that we are using 3/4 inch tongue-and-groove and there’s a reason for that if you’re bringing
in any heavy equipment into your shed heavy rototillers whatever it’s nice to have the extra stability of the 3/4 inch material it’s stronger and it’s only a couple dollars more a sheet this is tongue and groove fur now you might decide you want to go with pressure-treated if it’s available in your area but typically if you got the 2 by 6 joists regular fir plywood be the best try and avoid spruce other materials like that they’re not as strong fir tends to have a harder veneer now there are some considerations when you’re using tongue and groove plywood and I’m going to show you that we have a label on this sheet up here on the fence and you’ll find this on any tongue and
groove flooring plywood or sheathing as they call it you’ll have one side with a label on it that says place face down now that isn’t necessarily the best way to go if you are building a house and you have to go form to building codes yes when we’re doing this shed we’re not going to do that we’re going to actually put that face up you just got to make sure that your labels are all the same so if you put them all up they all have to be up put them all down they’ll all be down the reason that we’re not going to put these with the label face down is if you look
at this other piece I have on the ground here which I’ve already turned over this is the side that they’re saying should be face-up but if you look at it there’s a lot of knots here where the woods missing it’s not the best-looking surface so for the purpose of this shed we’re going to go with the other surface which is supposed to be the face side down because the veneer has much smaller knots they’re tight there’s none missing it’s going to provide a much better finished floor so that’s really about all you have to consider when you’re selecting your material so I recommend again 3/4 inch tongue and groove plywood for the floor pressure-treated joists for your framing
Continue the Shed-Building Series
Follow the lessons in sequence so each completed stage is ready for the work that follows.