The road to Ben Nevis Nov 2009

The road to Ben Nevis Nov 2009
The road to Ben Nevis Nov 2009

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Sunday, 30 June 2013

Stupid Great Tit!

First thanks to Llendorin who corrected my assumption in 'Blue Tit Ways'. Here's more information. There are several differences between the blue tit and the great tit, but the most obvious even in black and white, is the white area above the eye in the blue tit. Great tits have a black head piece which extends to just below the eyes.

Second although I've been thinking 'Exclamation Mark!' since the disaster, after reviewing the pictures again I'm wondering if it should be 'question mark'?  Great tits do look alike - has the occupant changed since a few weeks ago? Also - is it possible that disease has played a part in this story?

Blue Tit Ways explains that our nest box was adopted by a bird which layed 7 eggs. It sat on them for two weeks day and night with only short breaks until one day, early in the morning, it disappeared. A nest without a bird is very concerning when you are used to it always being there filling your screen!

By evening it seemed to be back again and, over a period of a week, it was in residence only at night time.

Then it began to sit through both night and day again. And we noticed the number of eggs was increasing.

addition eggs appeared
Supporting partner

13 or 14 was the final total. Fulltime sitting started around 3rd June and by 15th two hatchlings had appeared.

two hatchlings looking blurry to left of eggs
parent planning how to deliver food

Hatching continued apace, and the parents continued to bring food to the young, reorganise the contents of the nest and sit. The 16th of June was a busy day. So was 17th morning, but in the afternoon something seemed to change.

The parents spent more time away from the nest - first 10 minutes, then 30 minutes, then an hour or so at a time in the course of the aternoon and early evening. The feeding became less frenzied. The interval between arrival of a parent with food and the opening of the hatchlings' mouths which for a short while was instantaneous became more and more delayed. Then fewer mouths seemed to open.

no open mouth to feed

By the end of the day around 7pm the parents arrive with food. The babies wriggle about in response to the presence of the older birds but their mouths are firmly closed. There are no takers.

That night the parents were absent.
all that's moving is a fly
And the next morning they make a brief visit at 7.30 with some food, but all that moves is a big black fly.

Saturday, 22 June 2013

Moving a greenhouse from there to here ...

From here ...
... to here!
If you google 'moving a greenhouse' you will find it a common theme. Practical advice suggests it is a straight forward task which can be accomplished in one long day - someone advises that with two people 12 hours is enough time to dismantle a greenhouse and reassemble it on a new site.

My experience is a little different. Although a simple task it required more time and, in assembly, considerable precision.

Taking down. There are two main jobs - removing the glass, and disassembling the structure. This greenhouse ("Solar" made by FAWT) uses bent aluminium clips and mastic to secure the glass, others use a combination of clips and foam strip.

Handling the glass requires gloves to protect and grip, and a tool may be required to free-up each pane. In my case clips needed to be bent back, and mastic needed separating from the frame. A long flexible knife will do the job. 

Aluminium clips holding glass against mastic and frame

tool for separating glass from mastic
The tool pictured here is not very flexible so careful handling is necessary to avoid cracking the glass. The mastic is hard when cold - it is easier to handle in warmer weather - and extremely sticky, so its advisable to gather loose bits before they stick to your shoes.  It is inevitable that a few panes of glass get broken, but mostly they are a standard size and replacements can be easily obtained from a local glass merchant. Cleaning the glass and scraping off old mastic is necessary before the rebuild process.

Much time will be wasted if you reassemble the stucture incorrectly. Find out if there are instructions available with pictures that identify the parts - some models may have these available online. There are two important aspects to these instructions - the identification of the parts (what goes where and in what orientation), and the sequence of assemble. Without instructions it is advisable to take pictures of all areas of the structure and perhaps mark or label parts to indicate relative position and orientation before taking it down. 

Clips and bolts and nuts are mostly standard, but there will always be some exceptions. Make a note of where the longer bolts and strange shaped clips are used. Also some spacers may be used around the corners. Carefully store all these bits because you will need every last one!

Transport. Glass is heavy and moving it requires a bit of care. I found the stack in the back of my car fell appart as soon as I came to a roundabout. The aluminium frame is light of course, and it is the pieces that go down the whole length of the structure that may limit the possiblities of transport.

Preparing the new site. The position for a greenhouse requires some consideration about orientation in relation to the sun and surrounding trees and building as well as the nature of ground surface on which it is placed. In full sun a greenhouse gets very hot. My garden has trees which shade the structure except in early morning - probably not ideal but OK for me as my main interest is in seedlings and young plants which need protecting against direct sunlight.

I managed to take the original set-up down by myself, but I could not imagine assembling it again in a true square fashion without help. I arranged for a Visiting Engineer to be present for the preparation and build phase. I expected to follow instructions about mounting the structure on prepared ground with concrete slabs.

The Visiting Engineer soon put me right about that! First - a flat area is not necessary, the important thing is that the corners are level. Second - after a 'stress test' done by hitting my paving slab with a hammer, slab was deemed unsuitable and a high density concrete block was used instead to support each corner.

slab after 'stress test'
high density concrete block

Soil is compressible - depending on moisture content - so we dug out a small hole at each corner and replaced the soil with gravel on which to rest the blocks. This provided stability, and was also easy to manage when adjusting levels.

The four corners are made level, then the positions are confirmed by placing the greenhouse base on the blocks and ensuring the diagonals are of equal length. Holes are drilled and one side of the base is anchored to the concrete. The other sides are anchored later once some of the structure is in place.

Construction involved bolting together pieces (only finger tight at this stage) with the following stages -
  1. front (door) end
  2. back end
  3. the sides
  4. roof and roof window
  5. the door
  6. level and true-up (check verticals) and put (diagonal) tie bars in place
  7. glazing
  8. final true-up (squaring and level) and fixing - bolting down to remaining blocks. Tightening bolts.
A unanchored greenhouse can be lifted and moved by a gust of wind. Although firmly anchored to a concrete block at each corner, to be sure it would not lift we placed another block on top of each corner piece.

Glazing. On this greenhouse mastic and aluminium clips are used. As mastic is so messy it is necessary to start anew with this. Old mastic must be removed from the glass and the frame; new mastic must be purchased - this is in a ribbon strip on a large role. I also bought new clips. The old clips could have been reused, but they were mostly bent out of shape and covered in mastic. Although clips can be bought in DIY shops mastic in this form is not generally available - I had to go back to the manufacturer of the greenhouse to get a supply.

Thanks to the help of the Visiting Engineer the largest part of the construction was done within a day, but this was only after the preparation of the ground and the clean-up of the glass and frame which took another day.