I have a garden shed (built to site shape by a handyman 5 years ago) which is not sufficiently waterproof (i.e. metal tools do rust). I now want to make use of the shed as a simple workshop space and not have my diy tools rust away. Money is an issue and I would like to do this cheaply. Apologies for the length of this post.
The shed is timber framed on a concrete base. It extends from the rear of our garage (a rendered breeze block wall and no internal access) and is clad with a single layer of tongue & groove. There are small amounts of daylight (knots, etc) in some of the timber. The exterior is due further treatment – but which? (previously used Ronseal water based product). The shed does not have any ventilation installed (advice has been “you need it!” and “you don't need it”!).
The roof is sterling board, covered with felt and overlaid with corrugated steel sheets. The roof join against the garage has lead flashing (recently added). I seem to have overcome all the roof leaks that previously existed.
Weather (south Devon) comes mainly from the south-west and that side of the shed get a hammering in heavy rain. The two doors are not a watertight fit and let in some seepage at floor level during storms.
My problem (apart from being old and fairly ignorant about DIY) is that I've looked online for advice and found so much contradictory stuff that I feel bamboozled. Add to that what well-meaning DIY neighbours have advised me – and it's got worse!
At the moment, I have been advised to put (home made) plastic sheet membrane panels in behind the t&g – I assume this means with an air space between them. I then saw an online suggestion to use bubble wrap in order to create some insulation. Is this a practical idea? I did wonder what might happen to moisture that does get in between the wall and the membrane: does just sit in the gap, does it drip down to the base of the timber frame – or something else?
I've attached a photo of the shed, taken from the south-west – this is the side that gets hit by the weather.
Anyway, if anyone has some thoughtful guidance, however obvious it might seem, it would be really appreciated. Please be gentle – I should have focussed on this sort of thing 40-50 years ago!
