How to build a DIY decking cover

Richard Brennan
Wednesday, 21st September 2011

Learn how to build a cover for your decking so you can enjoy your garden or outdoor space, whatever the weather!

When we moved into our house on Bainbridge Island, I could see that I would need to replace the deck. It had been exposed to too many soggy Puget Sound winters. That summer I pulled the old deck apart and sawed it into stove-sized chunks. We burnt it in our woodstove that winter. I didn't build a new deck right away. I knew I wanted a covered deck but couldn't quite figure out how to tie it into the roof of the house. The deck was situated in an "L" shape of the house and tying the deck roof into the valley required an expertise I didn't possess.

Rainwater harvesting on the deck

I let the idea simmer all that winter. By Spring I visualized a way to install a roof over the deck without touching the roof of the house. Build the deck roof above and extending out over the house roof. The rain would flow from the deck roof onto the house roof and into the existing gutters.

This idea accomplished a couple of things. The deck roof was higher, giving the deck an open airy feel, like it didn't have a roof. It also allowed a breeze to flow naturally through the deck space, keeping it cool on hot summer days. Putting a roof over our deck was like adding an extra room to our modest ranch-style house.

Starting a garden on your deck: Multiple purpose decking

Life in a small house requires multiple uses for all the space. Attics double as storage spaces. The spare bedroom doubles as an office. The dining room doubles as a craft and hobby room and the deck is no exception. The clear roofing material allows sunlight to flood the deck.

The deck is now a great place to sprout seeds and harden off starts for the garden. Through spring and into early winter, we enjoy the smell of air-dried clothes and bedding and save money on the electric bill as the electric dryer sits idle. The open roof design allows air flow but the roof from the house blocks out hard winds. This makes the best conditions for drying herbs, since it regulates the heat and promotes a steady, even evaporation.

Cedar wood treatment

I used cedar planking for the decking and because it's not exposed to the weather I didn't treat it. About every six months I will scrub it down with a stiff brush and Murphy's oil soap. I double the recommended amount and leave it on for an hour before hosing it off to let the oil soak in. Because it never gets wet, it still looks great after three years.

To protect the decking during projects we just cover the area with flattened cardboard boxes, which eventually find their way to the recycle bin. Folding tables and camp chairs, which we found at auctions and yard sales, work great for most projects and provide the flexibility of stowing them to make room for different projects, or a backyard get-together with friends.

The Method

Building the deck is pretty straight forward. If you want to do it yourself you can download free software on line. It allows you to design the deck in 3D and also provides a reasonably accurate material list. I got mine from

The roof was as easy as building the deck. If you're handy with carpentry, which I'm not, you won't have any trouble. But for those of you who have trouble with cutting angles and getting them to fit there is a solution, brackets. The home centers carry brackets for just about every conceivable angle and dimension of lumber. I highly recommend them for the carpentry challenged.

Steps for building the roof are actually quite simple.

Step 1 – Install the Support Posts.

If you are floating the deck roof over the house roof you want the support posts to be within 4" of the gutter. Set the pier blocks so that the post will rest against the inside surface of the deck's support frame. Attach the support posts to the decks support frame with carriage bolts and don't worry about cutting the support posts to length yet, just let them stick up. I used two 4x4's but one 4x6 would work as well. The support posts can be attached to an existing deck in the same way. Just cut out the deck boards and slide the posts onto the pier blocks beneath and bolt it to the deck stringer. I used pier blocks for the fudge factor, because they are moveable. I buried them to within 4" of the top and used adjustable brackets.

Step 2 - Cutting to Size

Once the support posts are in place you can measure from the level deck surface to determine where to cut them off. Cut the two closest to the house about a foot or two longer than the front supports, depending on the amount of pitch you want to your roof.

Step 3 - Install the Cross Supports.

The brackets worked well for a one man job. I installed the brackets on the support posts first and just set my cross supports into the brackets. Before you screw the cross supports in place, set them in the brackets and check the cross support for level.

Step 4 - Installing the Rafters

Once the cross supports are in place you can install the rafters. I used 2x6's for this because of snow load and better strength in a windstorm. Again I used brackets for attaching the rafters. I did notch them some to allow the brackets to fit better.

Step 5 - Support Blocks

Next I nailed in support blocks for rigidity and for securing my roofing material. I snapped a chalk line down the center of the rafters and then snapped a line at the center between the center line and the upper and lower roof edges. I just used standard lumber for the rafters and support blocks since they are not exposed to the weather.

Step 6 – The Roofing Material

I went with a clear polyvinyl material. It's flexible and almost bulletproof for toughness. It also filters out 100% of the UV rays. This kept the deck from having that dark, enclosed feeling most roofs give. I was able to access one side of the roof from the house roof and install the first row of two sheets, making sure they were square with the rest of the roof. Where the roofing panels join make sure to overlap the top sheet over the bottom at least four inches. This allows for expansion and contraction. I installed the rest of the roofing from a ladder on the deck. Be sure to dip the self tapping screws in silicone before drilling them in. It will prevent leaks later.

Doing things outdoors seems to imprint more vividly on our memories the sights and sounds and smells. Whether it's hanging out laundry, planting seedlings, carving pumpkins or just bundling up and sitting with a cup of coco and watching the snow fall, our covered deck is a great place to be.

Richard Brannan is a master electrician currently working as a senior electrical inspector for the City of Seattle. He is an amateur herbalist, freelance writer and homestead handy man. One of his passions is to keep stuff out of the land fill by finding alternate and multiple uses for things. An example of this is 'The Poor Man's Ceramic Knife Sharpener' published and made available on the web by Backwoods Home Magazine


ziajoaquin |
Fri, 02/03/2018 - 05:41

I'm about to start thinking about building a deck too. Thanks for all the great tips. Now when I do finally start thinking about it, I'll know what to think about.

Heard about Ipe Decking information

tujavun |
Thu, 28/06/2018 - 22:11

Through the survey, you can openly share your views and opinions regarding the Dollar General products & service offerings.

vivekdeopa |
Mon, 06/08/2018 - 06:06