I’ve been asked this question many times… Can you build storage under a deck? Many folks have space under their decks that is just not being utilized. It could be accessed or in many cases the deck framing doesn’t allow for storing anything.
The fast answer is YES you can use the underside of your deck for storage…If there’s enough clearance. If you only have 3 feet you can still store some stuff under it. If you have 7 to 8 feet then under deck storage is a great option while keeping the cost of building a shed low.
Another thing to consider is your deck waterproof? Many decks are finished with vinyl, fiberglass or a dura-deck coating that makes them waterproof. Some other types of decks are constructed using treated wood and deck wood for the finish, these are not waterproof.
Depending on what you want to store under the deck will determine if you need it to be waterproof or not. Ladders, toys made out of plastic, garden hoses and maybe a boat can be stored without being concerned about water dripping through the deck boards.
Other items can be stored with the use of a waterproof tarp to cover them. Any smaller items like pool toys or other small toys can be placed in a watertight container and stored under the deck. But if you need to store stuff that needs to be kept dry then you’ll want to consider installing a waterproof barrier under the deck to protect these items from water.
Building Storage Under a Deck
There are 2 main ways to build storage under your deck if your deck is low to the ground.
1] Drawers… Building a frame and mounting some drawers into the space is simple to do and can provide some extra storage that you can access anytime you want the items.
2] Hinged Skirting… Another great way is to build a cubby hole under the deck that you can access from the outside by opening a part of the skirting either with hinges or a removable panel.
I’m going to recommend the “TCH Hardware Heavy Duty 250 lb Steel Drawer Slides” if you’re going to be building drawers for storage under your deck. These drawer slides are ¾ inch heavy duty slides; full extension lets you get access to the whole drawer.
These also come in a variety of sizes from 12 inches up to 36 inches. They have 114 user ratings and 49 answered questions. Definitely a good choice from sturdy long lasting drawers than can withstand daily use. You can see them here on Amazon.
How Do You Build Storage Under a Deck?
I’ve looked at building storage under a deck that is low to the ground. Now let’s look at some options for building some storage when your deck is 7 to 8 feet or higher off the ground.
If your deck is waterproof than you won’t have to worry about water dripping thru and getting the storage area under the deck wet. This is the simplest and least expensive option.
Building a Storage Shed Under Deck [Waterproof Deck]
Step 1] Foundation… The deck is supported by concrete piers that extend down below the frost line and will have one or more wooden posts that support the deck and the deck flooring is built on the support beams. You may have 2 beams or one with the other end of the deck attached to the house.
You have several options for a foundation; the best would be a concrete slab. You can also use concrete pavers or even gravel. Not sure you can read my article “What’s The Best Shed Foundation Option For You” for the top 7 foundation options. You can read it here.
Step 2] Walls… When your building a storage shed under the deck you need to be sure if the ground is subject to frost heave. While the deck posts are installed below the frost line your outside walls and floor may be subject to frost. If you’re not in an area that has frost then you can build the walls from the foundation to the underside of the deck.
If you live in areas that have frost then you’re going to need to make sure you don’t attach any framing to the posts or underside of the deck. You can do this by leaving a 1 ½ space between the top of the walls and the deck structure. This will allow for the walls to move without lifting the deck.
I have attached a drawing of the best way to allow for wall movement without lifting the deck.
Here are the steps:
Step 1] Cut 3 plates for each wall.
Step 2] Attach one plate to the underside of the deck where the wall is going to be.
Step 3] I like to use a 1×6 attached to the top plate on the inside and you can use a 1×6 on the outside that is painted or stained to match the decks color.
Only attach the 1×6 to the top plate, the second plate and bottom plate are used to build the wall so there’s a 1 ½ inch gap between the 2 top plates. Don’t attach the second plate to the 1×6, this will allow for the wall to move up and down in the space.
Step 4] Frame the wall with the second and bottom plates and slide into place on top of the foundation or treated beam.
You can use a wider piece of wood for the top plate to allow for the exterior sheeting and for any interior finish. Make sure you leave a 1 ½ space from the top of the outside finish to allow for movement. You can adjust the width of the top plate so the outside 1×6 covers the exterior finish too.
If you need some help with the wall framing you can read my article “How to Frame a Wall the Right Way” where I go into detail the framing process and step by step guide for framing in windows and doors. You can read it here.
Step 3] Doors and Windows… You can add windows to your shed to let more light in. You can add a single or double door to suit your requirements.
Step 3] Exterior Finish… This is the last step and you can match your homes finish to give the shed a blended in look.
To help you I have found a good video that shows you a good example of a storage shed built under a deck.
How To Build a Storage Under a Deck
Building a Storage Shed Under Deck [Non – Waterproof Deck]
If you want a dry storage option under your deck and it’s not waterproof you’ll need to add some type of drainage system on the bottom side of the deck joists to drain the water off the decks end or into a gutter that will take the water and drain it outside of the storage area.
I have found the easiest methods are using those corrugated panels that are used on some sundeck roofs; these are made out of plastic or fiberglass and are fairly inexpensive. You’ll need to attach some strips of wood to the bottom of the deck joists; using thinner pieces to thicker pieces will give you some slope.
Try to get some slope of 1 inch to 1 ½ inches so the water will drain away well. What works well is using a 1×4 at the end that is up against the house and using 2 inch thick strip of wood at the other end which gives you 1 ¼ inches of slope which will be enough slope to drain away the water.
Depending on how wide your deck is you can string a line between the 1×4 and the 2 inch strip and measure what thickness you need, every 30 inches should be good. If you want to drain away the water you can install a gutter at the outside and direct the water away using some down-pipes.
Building a Storage Shed Under Deck
Here’s the easiest way to build a waterproof roof under a deck that is not watertight.
I have attached a drawing and the steps below.
Step 1] Using a 1×4 at the end that’s attached to the house and using a 2 inch thick filler piece at the other end to give you the 1 ½ inch of slope required.
Step 2] Temporarily put the gutter up against the beam and mark the location about in the center of the gutter, this will be where the ceiling material will end.
Step 3] Move the 2 inch filler piece back a few inches from the end of ceiling material.
Step 4] String a line from the 2 inch filler to the 1×4 piece and measure the 2 center pieces and cut and install them.
Step 5] Install the ceiling material with waterproof roofing screws.
Step 6] Install the gutter and you can slope it a bit too direct the water away from the area or you can use a down pipe and run it away from the area.
I hope I have answered the question “How Do You Build Storage Under a Deck?” I have looked at the most common options and there are others depending on your situation and storage needs.
I have seen folks actually put a metal or plastic storage shed under their deck and it looks like a good option if you have the height. If you have found this article helpful, give it a share. Thanks for reading.