Monday 11 December 2017

Polycrub part4 :Sheets

The construction notes say that sheeting the polycrub is 'tricky'.

I would prefer a different description .

Fiddly, Awkward, Tedious, Frustrating, timeconsuming, Difficult will do for starters .

The sheets come off a low loader - 7 metres long and about 1200 wide .


First job is to place the sheet over the frame of the hoops. Don't attempt it on a windy day , they suggest. Excellent Advice , I'd add, after rugby tackling one is it tried to make an exit  corried along on a brisk westerly breeze.  So chossing a not-quite-so-windy day we started.

They are joined by a joining strip

So you need to join 2 sheets, 7 metres long, across the curve of the hoops.


The construction suggestions say  several pairs of hands will be necessary. - the plastic joining strip need prising apart enough to slot the next sheet in.

Obviously its something just right for a husband-and-wife team. After  our first attempt , i had a chat with Smiddy Cottage Garden Services , who have installed them before.

He asked

  • "how long did the  first go had last ?"
  •  about an hour 
  • "Wow , as long as that ! "

So clearly not something for a husband-and-wife team to attempt.

But I got the hang of  it.

You need to replace your wife with 4 breezeblocks, 10 metres of rope, sundry wallpaper  stripping tools, fish slices and some custom -made plastic wedges.


Firstly, get sheet over hoops, then attach in place with acoupld of clamps at the free end.
Place breezeblocks approximately 6 inches from joining strip , with rope across the sheet to the other side. This will hold the sheet in place ( even when its windy).




The hoop is approx 2.5 meters offthe ground, so you need some access . Several ladders and bit of wood to get the ladders in the right place does the job .



Then.

Hold the joining strip apart with some whatevers, and tap the new sheet into the join. Start at one end and work your way round to the other side. The problem is that the curvatures of the 2 sheets may not be the same . the alignment may not be the same .

You need the wedges, pie slices, wallpaper strippers at various times. Sometimes you need them all together . The rope is a convenient way of stopping them sliding off - well mostly stopping them sliding off - and also provides some leverage to keep the joining strip open.





It took between 90 minutes and 3 hours per join. And then about 20-30 minutes to screw each sheet in place - 21 screws per sheet

The most tedious bit of the whole job ?

Covering the screws themselves with the  little plastic cover. It needs cutting off , holding over the screw head then tapping in . OK if you get it first time, but the plastic is quite soft and deforms if you dont get it right first go.





After a few bashed fingers and  dropped covers I'll leave this bit for the  summer when you dont need thick gloves for working outside . Or i might just put some white mastic sealant over all the screws to make it look nice. Or I might not.

it looks OK with the neat row of screws , doesn't it ?