Old Schoolhouse Internal Renovation

1. Schoolhouse Floor Plan

Table of Contents

Past renovations

The school ceased operation in 1945 but was retained as a residence for the teacher at the school nearby at Roslyn. "Cottawalla schoolhouse" was listed as a polling place for the 1965 state election. At some point it became a private residence and has had at least three previous private owners.

I don't have datings for some of these but past renovations and modifications included:

Timbers

The original flooring is 130x24mm T&G hardwood timber, most likely to be Tallowood. This is a very dense and hard wood. All floors are very worn in places but don't appear to have been sanded since originally laid. The classroom floor has certainly been lifted and put down again to compact it. Various access points have been cut into the flooring, at least one per room, to install the oil heating ducting. It was clearly intended that carpet would be laid to hide this work, hence the finishing is rough. It appears that no effort was made to lay ground sheets when repainting, for the same reason. Gaps between floorboards and some depressions were filled and leveled with plaster.

All of the original skirting boards, door jambs and windows were made from Australian Red Cedar (Toona Ciliata). The original finish was a shellac. The species was highly sort after and harvested intensely all along the east coast during the first century of the colony with much of it exported. Today Toona ciliata is very scarce (regarded as "commercially extinct" and difficult to establish millable quality plantations due to Tip Moth attack), and so what is obtainable is very expensive (AU$8,000 to AU$10,000 per cubic metre up to 50mm thickness from salvaged trees).

The 150mm x 20mm cedar skirting boards (estimated value at AU$24 to AU$30 per lineal metre and possibly much higher for long lengths) will be replaced throughout the building for consistency but kept as stock for repairs, to windows initially.

New Renovation Plan

Nothing structural is planned but the interior needs to be repaired and updated.

General

Originally the classroom, the lounge the most work. I will give it new wall rendering after stripping the old rendering off, replace about a third of the flooring, convert the open fireplace to a modern high efficiency enclosed wood fire, and restore all four windows.

Originally the parlour and entrance to the residential section, I will reopen the fireplace and two doorways that have been closed off since 1983, restore the window and put down a new floor. The gyproc ceiling and lining installed in 1983 will be removed to restore the original room proportions.

Originally the main bedroom, I will reopen one doorway that has been closed off since 1983, remove a built-in wardrobe, restore the window and put down a new floor.

Originally a utility room and the kitchen, I will restore the windows and put down a new floor.

Nothing was planned for the roof space until I saw what was inside. Above the two bedrooms unused ventilation ductwork and the old glass fibre insulation will be removed and the ceilings vacuumed before plaster and lath preventative reinforcement is done. New insulation will be installed. There could be some rewiring to be done here as well.

New Flooring

Bedrooms one and two, the den and sitting room will all get new flooring. The existing subfloor structure will be repaired, levelled and rebuilt before new solid timber overlay boards are laid over 19mm structural particle board sheets.

The overlay timber will be solid 130mm by 14mm planks of Sydney Blue Gum. The resulting fully bonded floor membrane will be 34mm thick on leveled and stiffened joists making for an exceptionally solid but traditional feel under foot.

Overlay acclimation

The lot was unpacked and stacked inside to acclimatize for the next year, or two or three or four, while I finish the subfloors and walls etc. The room has been kept dark to avoid discolouration of the exposed timber before it is laid.

2. New solid timber overlay flooring has arrived.

3. Acclimatizing in the old classroom

Overlay installed

The next four images were taken just after laying the floor. Temperatures are falling fast so it may be a while before it's warm enough again to apply a finish. Six months later: it's now [just] warm enough for the finish but it's been a very wet winter and spring and I want to wait until the moisture content of the timber falls back to the level it had when laid.

5. Bedrooms One and Two

6. Den to Bed two

7. Bed one to Sitting

Crawlspace access

To facilitate maintenance of ducting, wiring and any other work under the floors, at least one 600x450mm floor hatch will be installed in each room. It is not possible to move between rooms through the crawlspace.

I've recently completed a room for a friend where I built the subfloor and installed a hatch with solid timber overlay using the same technique as I'll use here. Here are some photos of that floor, taken prior to sanding and finishing.

This experience suggested a different method of matching the hatch cover overlay to the surrounding floor. Ultimately though, it would have been less time consuming to cut the boards and fix them to the hatch cover at the time of laying the floor.

8. Dress rehearsal floor and hatch prior to sanding and finishing, done for a friend.
The timber used here was Blackbutt.

9. Hatch close-up

The floor hatch lift handle was removed before sanding and finishing so it's recess in the hatch door will need to be deepened for it to fit flush again.

To do that I made myself a hand router plane (YouTube is your friend). It's a simple offcut of Merbau hardwood with an old chisel jammed through a hole. I've carried that broken chisel around for 50 years and finally it has a use again.

10. DIY router plane

11. The completed hatch in the den. Now the floors can be sanded with the hatches in place then finished.

I've chosen to finish the floors with Cabots oil based polyurethane clear gloss. The deeper tone and gloss finish I think suit the period of construction.

First, the floors need to be sanded, not too aggressively though. So hiring a drum sander was skipped in favour of a heavy industrial grade rectangular pad orbital sander. I also hired the obligatory edge sander.  Hired for a week, it took all of that without rushing to get the floor to the second finish coat. I'll need the orbital again for a couple of hours to complete the third coat.

The four rooms total roughly 50 sq.m and five grit grades were used in this order: 40, 60, 80, 120, fill, 120, 180, with vacuuming after each grade.

12. After orbital sanding with 40 grit

There was some very slight cupping of the boards at the start after they were left bare for several months while it was too cold to apply the finish, so I ran the wide orbital across the boards before finishing with the grain. This was especially necessary for each grade after the 40 grit to ensure all sanding scratches were removed.  The floor will not be billiard table flat but I'm not aiming for that anyway. I want it flat and smooth under foot but with slightly imperfect reflections.

After the 120 grit, the entire floor was filled with Bona Mix and Fill combined with 80 and 120 grit dust from the edge sander. This was followed by a second 120 grit sanding, vacuuming. The whole floor was then tacked with a frequently rinsed and rung-out microfiber pad to raise the grain before the final 180 grit sand and vacuum. A final repeat tack was done to remove any remaining fine dust. There should be minimal raised grain after this second tacking.

13. After the first finish coat

14. First coat sanded 240 grit

Gloss polyurethane also needs to be sanded between each coat with 240 or 320 grit to provide a key for the next coat. I used a 240 grit pad on the orbital sander.

Visibly the finish attains another level after the second coat compared the first, appearing much more even. I'll leave the finish to fully harden for a few days before final sanding and a third coat, or perhaps wait until after the skirting and remaining architraves are done.

15. Second finish coat still wet

General

Windows

There are six exterior windows plus two that were originally exterior and are now interior (looking into the main entrance hall). With the restoration, I have started with the three under the southern verandah because they are in the best condition and under cover. This will provide a gradual learning experience and hopefully avoid major and/or costly mistakes being made.

As it has turned out this was the right decision. Each window has provided small challenges that have been different for each window, which is an almost ideal way to learn.

The remaining three exterior windows will be significantly more work to restore.

Refurbishing the windows may include some kind of thermal treatment.

Wiring

The building was rewired in whole or in part circa 1983, which is probably the last time electrical work was done in this wing of the house. In 2012 all the old wire fuses were replaced with circuit breakers of equivalent or lower capacity, which in turn will likely be replaced in the future by residual circuit breakers.

A single 16A power circuit and a single 8A lighting circuit service the whole of the old schoolhouse section of the building. 

There are currently no appliances that require high current draw, and none should be required in future. The separately wired and breakered ducted heating and cooling zone covering the schoolhouse section, combined with an efficient wood fire, should mean that items like electric radiators are never required. The highest loads are likely to come from entertainment equipment and hair dryers.

I want to increase the number of GPO locations in all rooms for convenience and to reduce the clutter from running power leads across floors etc., also increasing safety, and so, several of the existing double GPOs may be converted to singles, if need be, to maintain compliance with wiring rules.

Painting

Of the original residence rooms three have been painted using non lime-based impermiable paint systems. These will stay as, of these walls, only one wall in each of two rooms are fully internal and are thus not susceptible to moisture ingress. The heating/cooling system should deal with condensation build-up. The two walls with an exterior side are under verandahs and do not appear to have suffered any effects of moisture entrapment. The remaining room (the original parlour, now bedroom one) had been mostly wallpapered before being lined with gyproc sheeting. Removing the remaining wallpaper revealed the original milk-painted walls. All surfaces above the picture rail, including the ceiling, had been painted with oil paint and later acrylic paint. The walls have been stripped back but the ceiling will not be stripped.

I've decided to lime wash the walls in all four rooms plus the ceilings in the two bedrooms. A compatible preparation undercoat will be applied to all surfaces to which lime wash will be applied.