This instructable aims to explain how to make a patio or terras roofing. It's made out of Douglas pine wood and the whole construction is build upon 6 steel M20 wire ends. The goal was to make this cost effective. I did some research and ordering a Terras roof with these dimensions (4 x 5 meters) and having it build by professionals (adding labor costs) will set you back anywhere between 2.000 and 5.000 euros (2.275 to 5.690 dollars) here in Holland. My aim was to keep it below a 1000.
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Step 1: Ordering Lumber and Materials
This proces can take pretty long depending on where you are going to buy your lumber. In my situation I ordered freshly cut lumber since that was that cheapest option. The downside was that I had to wait a few weeks untill the miller had my order ready. I also searched for a small lumbermill that had a nice price per m3. Here in Holland prices seem to vairy alot! Would I order the lumber (only for the pillars and ring beams) directly from a store it would set me back at least 600 to 800 euros. The lumbermill where I finaly placed my order charged me 350 euro.
I could have picked oak instead of douglas pine but that would almost double the price. A plus side of Douglas pine is that the wood is very soft and thus very easy to work with.
So I bought to following:
- 15x15cm Douglas pine for pillars and support beams 350 euro
- 2x20cm Douglas pine boards for cladding the sides and the rooftrimming 200 euro
- 4x4cm normal pine beams for roof support 50 euro
- OSB sheets (pressure glued sheets) 125 euro
- EPDM incl adhesive (rubber cloth like you use in ponds only better suited against UV from the sun) 300 euro
- Screws and wire ends 25 euro
End total is a bit more then the initially budgetted 1000 but hey, who's counting.
Step 2: Foundation
For the foundation there are a couple of methods you can use. In another instructable I made about a toolshed I painted the pillars with anti-rot and put them directly into the ground. That was pressure treated wood and the Douglas pine I am using in this build is not. So I need the pillars to be above ground to prevent rotting wood. That means I need some solid foundation and a construction that lifts the pillars above groundlevel. There are different methods for this aswell. You can use U-shaped clamps that can be fastened in the cement. The pillar can then be mounted between the U-shape with a few screws. You can also use PVC or some other flexible water resistant material in between the concrete foudation and the wooden pillar. Just make sure the water can not get high enough so it can touch the wood.
I chose for a simple and cheap solution: M20 wire ends. These pretty heavy wire ends are 30cm long en have 1 extra feature: you can use the nuts to adjust the pillar height in case you have made a error. I also made a few big washers (4x4cm) out of some steel plating. These go in between the nut and the wooden pillar.
Then it came down to carefully measuring out where the wire ends needed to go. I used rope and a tapemeasure to align everything and I eyeballed the depth of the wire ends. For each hole I used 1 bag (25kg) of quick drying cement. One of the corners was taken up by a big stone planterbox (hey, another instuctable about that pretty soon!) so I had to drill a hole in the stone. I made a very watery cement paste that I poured into the hole before I put the wire end in it. Well let's just say that will go nowhere anytime soon.
Step 3: Pillars and Beams
Let the fun begin! Personally I love this kind of woodworking although I'm just a bloke with a few tools and not a proffesional by any standards.
I started with cutting 5 wooden pillars to the exact same lenght. (and 1 shorter for ontop of the planterbox) You'll need to get the misses involved here since this step is crucial in sorting out the overall hight of your patio. So you don't get blamed afterwards. I believe we went with 2,15 meters.
Then I drilled a hole in the center of the pillar. Just draw a few lines from corner to corner to find the exact center. Before I put the pillars on the wire ends I poured a bit of constructionglue in the hole and made sure the nut and washer where at about the right hight on the wire end. As soon as the pillar was on the wire end I quicky braced it with a few scraps of wood and checked if the pillar was level and square. Note that you can still adjust the height with the nut. When all 6 pillars where in place I checked the measurements again and did some tuning up.
Now it was time for the beams. My method was simple: no measuring when you don't have to. Just put a beam ontop of 2 pillars and trace the end with a pencil or something sharp. You can't go wrong. Ofcourse you'll need to measure other things very carefully like the depth of the cuts for the joints. For the joints I chose the interlock the beams by cutting a half out of every beam so they would fit neatly into eachother. To fasten it I used woodglue and 20cm long self-drilling screws.
Step 4: Roofing
For the roof I used the cheapest materials I could find: 4x4 pine beams and OSB sheets. This is also the step I would like to redo. I absolutly hate the look and feel afterwards. I was planning on a lower (double) ceiling I would be putting in later together with LED spots. This way the cheap pine beams and the OSB sheets could not be seen. When I tried that it just didn't look right. The lower ceiling made the whole structure look as if it was build to low. So i scrapped the double ceiling and now I'm left with these cheap materials in sight. Not everything can go alright I geuss. Perhaps i'll scrap the whole roof and make a nice triangular roof when I have the time. Not sure yet.
Anyway, the cheap pine beams and OSB is simply screwed inplace. Nothing fancy here. When that was done I made an upright ledge ontop of the roof around the edges. I made a diagonal cut along the lenght of a pine beam to get 2 exactly the same looking triangular shapes. I did this to avoid gleuing in the EPDM rubber in a 90 degree inward bend. The EPDM kit came with a gutter piece that took a bit of brutal hammering to get in the right shape.
Then it was time to get gleuing on the EPDM rubber. This stuff is exactly the same as the rubber you use in a pond except that it is better suited against the UV radiation from the sun that dry's out rubber over time. Whenever I need to glue in EPDM again I'm not going to do it the way I did it with this patio build. I glued up the first half and then the second half. Those pieces where way to big to handle since the rubber is massive and heavy. This stuff is very sticky aswell and it almost turned out wrong. I still have a few nasty folds that I couldn't roll out afterwards. Next time I will spread the rubber, lay it precisely in place and then roll it op to 1 side. Then i'll glue in 1 meter and roll down the rubber and continu this proces untill its done. In the end it turned out ok though.
Step 5: Finishing Up
This step is pretty straight forward. I took out my fencing since it stood in the way and started nailing on the boards for the sides. This not only looks nice but gives the structure some much needed strenght. Lastly I made some rooftrimming from the leftovers. The trimming consists out of a front trimming and board on top with a little hangover. This way they rain cannot seep between the rubber and the trimming. I could have gone for the nicer stainless steel trimming but that became exspansive pretty fast.
lastly I added some DIY lighting (christmas lights crammed in a few lanterns) and some furniture to make the patio a bit more cosy. For that nice propellor in the last picture you can check my other instructables. And yes, I'm also making a instructable about that fireplace!