Wednesday September 9 – Friday September 11
Back to work
It had been hectic to get the slab poured in the middle of winter to meet the deadline for the First Home Builders Boost. After that the builder and I decided to wait a couple of months before starting work again – this allowed for a quick holiday, for the weather to warm up and the ground to dry out.
I tend to do the dirty, unskilled jobs on site, such as digging holes for the footings, lying in the mud to clip feet on trench mesh, barrowing concrete, carrying timber, etc. Being the designer and the owner, I also read dimensions off the plans and provide the setout for the builder. Marking the first wall out on the edge of the concrete slab and realising the floor is 100mm shorter than it should be was a terrible feeling. How did we get it so wrong? The footings were measured, the blockwork was measured, the slab was poured – the floor was built! It had us scratching our heads for a while (the builder even called for a tea break) until I realised I had provided the wrong dimensions for the setout! Turns out we were 10mm short in both directions (the width of a mortar joint in the blockwork) but that’s OK – I could live with that.
Quick and easy
When you get two experienced builders working together (Greg and Pete) things can go up quickly. Once a jig was built and the drop-saw set up with a set length marked it was efficient cutting all of the same length studs. The wall is then assembled flat on the slab. Damp course membrane is tacked to the underside of the bottom plate to prevent moisture rising into the frame. Metal strap bracing connects the studs to the bottom plate to prevent uplift; the same type of strap bracing is used to connect the top plate to the stud. The wall is then lifted into place.
The wall is held in place with temporary bracing to prevent it falling over. Dynabolts fix the bottom plate of the wall into the concrete slab. At the end of the first day framing we had the first wall up and the second wall ready to lift up into place.
Spread the load
Lintels are the larger horizontal pieces of timber across the top of the wall. Lintels spread the load from the roof across the top of the windows and are notched into the studs to sit flush. The size of the lintel depends on the size of the load and the distance it is spanning across. Most of the weight to lift up in these walls were in the lintels – the pine studs aren’t that heavy.
Once the walls are lifted into place and bolted to the slab, each wall needs to be braced to tie all the members together so the wall is vertical and square. Structural bracing is needed to prevent the wall from twisting and helps to make the structure rigid. For timber frame buildings there are two basic types of bracing: plywood or metal strap bracing. We are using 4mm hardwood plywood bracing. Because the material has a thickness (4mm in this case) we could either rebate the studs where the bracing would go for a flush finish with the others studs, or cut strips of ply and pack out the other studs – we have opted for the second option.
Two for the price of one?
The internal walls of 60k House will be lined with plywood and painted with a whitewash – durable, light in colour but still with the natural material showing through. It was a late consideration to use the internal ply lining for the structural bracing – why double up on material when one sheet can serve two purposes: bracing and lining? I rang around a few suppliers to see if we could get 2700 long sheets (the height of the walls) but in the end decided to stick with the original plan. Next time…
I will talk more about the roof trusses and roof framing next time.
Costs: framing, brace ply, nails, screws and bolts – $3,697; generator hire – $100
Disclaimer: Any advice contained within this blog is of a general nature only and cannot be relied upon. Details provided are in good faith and relate specifically to this project. Any author will not be held responsible for advice or information presented.