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2016-Jan-23 - Wooroloo - Loft Floor Joists #24
During this week, whenever I had a chance I worked on creating the fold up tarpaulin support that I mentioned last week.

The finished upright is about 3.0 m high and 2.4 m wide.

On various days I visited Midland Timber for 45 x 90 H2 pine and strapping and Bunnings for bolts and nylon rope.

I constructed the upright pretty much as I mentioned before - ie one rectangle inside another with diagonal braces.

However, the main issue I found was keeping control of the upright as I raised and lowered it.

In fact, at one point, the upright experienced a "spontaneous uncontrolled rapid self reconfiguration event" - ie it fell over.

I realised that I needed a lift up "bumper" to initally set the upright at 30 degrees from the horizontal.

This can be used for lifting (reduces the force required significantly as tan 60 deg is significantly less than tan 90 deg - infinity).

It also can be used to make the lowering process much more controlled as the weight of the frame can be lowered on to this bumper.

I also placed knots in the lifting ropes in appropriate places so that the unsecured frame will initially lift up to 5 deg over the vertical keeping it safe until the diagonals are placed.

I realised that the lifting rope needs to be tied off to something substantial to keep the frame safe.

In use, the outer frame will need to be clamped securely to a joist to prevent it sliding while raising or lowering the upright.


I was out on site at 5.30 am but waited until 7.00 am before I started any work outside.

Following rain during the week, the tarpaulin had 6 rather large water ballons.

I managed to empty these by a combination of pushing from below with a broom, and releasing the corner attachments so that some parts dropped right down on to the temporary roof.

Fortunately no damage had been done to the tarpaulin.

Installing the upright on to the loft floor was difficult work - particularly as there is nothing yet to stand on.

All I could do was use the hallway walls and a step ladder.

To lift each of the two main frames up on to the loft floor level I used some 4 m lengths of timber leaning against the front wall and a rope thrown over the front steel beam to do the hoisting.

Then, as the frame teetered at its halfway balance point, up on a ladder to push it over the hallway.

Working off a ladder, I slowly and cautiously installed and bolted all the components of the upright.

The biggest problem was the bumper section.

At home this worked easily because I had a base to stand on.

Out on site it seemed very heavy, rather unpredictable and dangerous.

Eventually I brought it under control by temporarily inserting a purlin across the width of the room so that it had something definite to rest on.

Initially I had tied some rubber matting on to the sharp corners using rope but I could see this was unreliable.

I decided to use cable zip ties and stow the frame, at the end of the day, in a slightly elevated way so that I could leave the bulky rubber permanently tied on.

As I was doing this, Jim and Sandy turned up.

I wasn't quite ready to raise the upright in to its operating position (I still wanted to tie on an extra piece of tarpaulin as a street front apron to stop the intense 7.00 am sun coming in from a low angle).

However, while I had some help it made sense to get it erected - so I am very grateful to Jim and Sandy for their help.

We stood around and chatted for half an hour, after which I had a break.

By dropping the "flag pole" ropes it was relatively easy to attach the front apron piece and after a bit of wrangling I had the tarp flying the way I wanted it - the apron pretty much hung down at the front of the building and part of the main tarp was lifted well up by the upright.

This gave me a good working area covering about half of the loft floor area.

The concept was working - around midday, when all exposed surfaces where too hot to work on, it was relatively comfortable under the tarp.

My plan of attack is to install all the C 100 purlins in the three wet areas, install some temporary flooring over these purlins, and then use these areas as a "beach head" to work from to install all the Z150 purlins.

I am visualising having a small area of elevated deck to perform all the cutting, notching and drilling of purlins on, rather than running up and down a ladder 200 times in one day.

I will also move the upright on to one of these completed areas. Rather than just picking the tarp up at one edge, it can support the tarp centrally giving me protected access to the majority of the loft floor area.

Hopefully after spending two weekends on the tarp and its support, it will improve my productivity for the next few months.

In the mid afternoon I measured up all the lengths of C100 that will need to be installed and jotted this down in a notebook.

I then spent about an hour and a half inside working out the most efficient way of cutting up C100 lengths to minimise waste.

Back up on deck I cut a couple of 2100 mm lengths and pinned them back to back using 12 gauge x 30 mm fine pitch tek screws at 150 mm spacing.

At this point a thunderstorm swept in.

I hurriedly piled all my tools in to a wheel barrow, pushed it under shelter in the undercroft, and retreated inside until the worst was over.

A little later I emerged.

A corner eyelet had been torn out during the brief storm. Also one of the pulleys had jammed.

I performed a work around for the torn eyelet and made a mental note to drop one of the "flag poles" next week and rework its pulley.

I then needed to spend quite some time putting away materials I had used in the early morning.

After this I decided to drop the tarpaulin completely to the deck and detach it from the flagpoles.

This way I could avoid any further damage during the week and I am now confident that I can relaunch the tarp relatively quickly, particularly after discovering how useful a broom is for making adjustments from underneath.

I wheeled out all my tools again and as darkness fell I was able to complete the installation of my first purlin.

A lot of learning was involved today - I hope I can speed up next week.

I no longer need to stop working at 10.30 due to extreme heat on the temporary roof, but can keep working under the protection of the tarp. I hope I can get a lot more done in future.

Components of the stand

Stand partially raised by lifting on to bumper

Fully raised and locked with diagonals

Bumper stowed horizontally

Upright installed on the loft floor