Building Granny Flat. Step 15: Tying down the structure

You have installed and fixed rafters for all building and the veranda. The next step is tying your granny flat down with steel rods system.

Steel rods from the top

Expert’s Tip #1: “Start your hold down rods with a bit of preparation. The rods have a winding lock nut on top, a self locking system. When the winding nut gets to the top, it will keep free spinning. So, grab the claw or a hammer or some pliers or a chisel and just pound over the top of the rod, wind the nut up and it will stop spinning. And an idea behind that is when you are doing the nut underneath, the rod won’t twist up at the top. You’ve got no access to put a spanner on top of this, so you don’t want spinning off and the rods lost in the wall.”

After the preparation of all steel rods, drop the rods down into the walls. Have your mate underneath to locate the rod at the bottom and put the washer and nut on. From the top, get a hammer and bang the rod down to be flush with the timber surface. The timber is quite soft, so bang it down carefully. Your ceiling boards will go right over the top. So, do not leave the bumps.

Steel rods at the bottom

Expert’s Tip #2: “When doing your rods, putting rods through the walls they come right through under the beam. Tension up the rods very firm, but do not over tighten them. If you over tighten the tie rod, you can put a twist in your wall. So, get them up very firm but do not crank it up over the top, because you can bow your wall.”

Important. Prevent jamming of the nut at the bottom of your steel rod. Always paint a little bit of Anti-seize on a thread. It’s very important because it stops a fusing of the nut into the rod. So, when you need to re-tension the rod you will be able to adjust. If you miss this step, you won’t be able to tension up your rods. It may cause problems down the track. So, Anti-seize is a very quick solution. Put it on every time on all the rods.

Re-tension the rods

Your building will settle within the first month. Because of steel rods tension and the weight, boards will come closer and tighter. So, check your rods after 2 weeks and then after a few months. Also, if you live in dry climate conditions, timbers will slightly shrink and vice versa. Leave your rods looser if you think timbers may swell a bit. Either way, if there is any movement, come back and re-tension or readjust your rods.

Now your building is tied down to the foundation. The next step is to put on the ceiling boards. All granny flat building steps can be found on Builders Guide page.