Nearly done: lining the end wall of the bedroom

Insulation & Wall Lining

Andrew Kerrby author page

5 comments Construction

Thursday November 19, Friday December 4 / Monday December 7, Monday January 25

Pack ’em in

See the previous post about ‘Putting up the Ceiling’ for an explanation about the role that insulation plays in keeping a house warm in winter and cool in summer. For insulation to be effective it has to block all gaps or cavities – including being squeezed in between studs and window frames. This serves to eliminate droughts and also provide resistance to reduce heat transfer. BUT… Batts need to be expanded to their natural depth and density – if they are squished in or compacted too tightly then they won’t be as effective. Batts also need to be fitted around wires and plumbing so there is no air gap for heat transfer.

 

Line 'em up: the wall batts fitted in between the timber studs

Line ’em up: the wall batts fitted in between the timber studs

 

Caution: take care when cutting batts around electrical wires

Caution: take care when cutting batts around electrical wires

Cut ’em up

In the walls we installed R 2.5 batts – the dimensions of each batt is 1160 high x 430 wide x 90 deep. These standard dimensions make it easy for installing batts in a standard timber frame wall – 2400 high with studs at 450 centres. I soon realised this when I had to cut each and every batt to make them fit within the 2700 high wall with studs at 400 centres! The spacing between each stud is because of the 1200 grid – dictated by the size of the four large windows and a nominal apple crate (check out the post ‘Design – Part 1’). Those early design generators that determined the grid was coming back to rub tiny glass fibres in my eyes!

 

Poker: stuffing the batts in between the stud and window frame

Poker: stuffing the batts in between the stud and window frame

 

All over: batts packed around plumbing pipes and electrical wires

All over: batts packed around plumbing pipes and electrical wires

More to it

Just like the ceiling, the sheets of ply for the wall were cut to size (some at Greg’s workshop) and arised by hand before being fixed in place with a nail gun. It took longer to fit the sheets of ply for the walls than it did for the ceiling – or at least that’s how it felt. Then again – there is heaps more wall than ceiling. The joins in the sheets are staggered and reflect the various heights of the windows, which reference the nominal height of stacked apple crates. We have made considerable effort to minimise wastage in material by using offcuts where possible.

 

Made by hand: Greg arised each edge of the ply sheet with a hand plane

Made by hand: Greg arised each edge of the ply sheet with a hand plane

 

Lining up: the stacked apple crate reference extends inside to the sheets of ply

Lining up: the stacked apple crate reference extends inside to the sheets of ply

After thought

My original idea was to clad all of the timber framed walls (except for the bathroom) with plywood. I even bought enough sheets of ply to do this. Then I gave the kitchen and laundry some thought and decided if the joinery was going to be black (form ply), and the splash backs too, maybe the low section of walls that wrap around the kitchen should also be black? Another example of designing as we go. It did mean borrowing a mate’s ute again, taking back some sheets of ply and swapping them for sheets of form ply. The sheets of form ply for the wall are the same thickness (9mm) as the normal ply so there is no issue with the junction where the sheets meet.

 

Contrast: the black kitchen and light ply walls

Contrast: the black kitchen and light ply walls

 

Ebony and ivory: the two toned wall to the kitchen

Ebony and ivory: the two toned wall to the kitchen

 

Design Tip: Here’s something I discovered and is only obvious in light: the 2400×1200 sheets of 9mm form ply are made in China and are dark brown; the 1200×600 sheets of 16mm form ply are Australian made and genuinely black in colour.

 

The origin of ‘normal’ ply (plywood that looks like natural timber and isn’t used for forming up concrete) can also affect the appearance of the timber. There are products available from New Zealand and Asia, as well as locally sourced from within Australia.

 

Complete: an entire wall lined

Complete: an entire wall lined

Useful

In the previous post I wrote about my plan to attach some sheets of caneite to parts of the walls – to improve the acoustics (dull the echo of the hard surfaces) and to provide a pin board. While I was studying at uni I used to live in a great share house with a blackboard as a splashback – this was used for all sorts of lists and doodling. I will consider incorporating one around part of the kitchen in my shack.

 

Fun for the whole family: a blackboard splash back can be useful for lists and creative pursuits

Fun for the whole family: a blackboard splash back can be useful for lists and creative pursuits

 

Costs: plywood – $992; kitchen walls (black ply) – $174; insulation – $634;

 

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.

5 Comments

  1. Andrew – great update – I like the form ply. And thanks for thee handy hint on brown v black – I didn’t realise. I am thinking of using form ply for my window reveal material. I might now add it to elsewhere as well.

  2. Hey – I just posted another comment on “Putting up the Ceiling” – and this is related – I notice no inside membrane behind the walls. I guess the walls are not too think, but if you had thicker walls, in a cold climate, you might end up with lots of humidity (and perhaps condensation) in the walls if the inside is warm, and the outside is cold (and where you are in Tasmania gets cold in winter – I think it is climate zone 7 or 8). Plus, having an internal membrane stops draughts, and keeps the warm arm inside. You might have answered this already in “putting up the ceiling” – What do you think?

    1. Andrew Kerr

      Hi Hamlet,
      I will reply to this question in more detail to your other comment on “Putting up the Ceiling”. In brief, the only membrane in the walls is the vapour permeable Proctor Wrap. This membrane is beyond the insulation, on the outside of the studs. There is then an air cavity (and space for any condensation to run down), with the cladding (cement sheet or timber weatherboards) attached on battens. Will include a photo of the wall construction when we complete the cladding in a couple of weeks. And yes – Tasmania is in climate zone 7.

  3. Andrew, I recall reading your house energy star rating is 7 or so.
    I am wondering if you did any insulating sub-floor that boosted your rating?

    1. Andrew Kerr

      Hi JA,
      Yes, I did. We installed polystyrene insulation beneath the slab (100mm in the bedroom, 75mm in the living area). This is mentioned in the earlier post ‘Boxing Day’:
      http://60khouse.com.au/2015/08/23/boxing-day/
      The insulation has an average value of R1.8 that contributes to the improved thermal performance (and improved assessment). Having now spent some days in the house during autumn it seems to be working.

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