Insulation. What is the Best Choice for my Workshop?
Summer Big Build: The Workshop Insulation Project
Over the winter my workshop was cold. Very cold.
I quickly realised that simply relying on a cost-effective means of heating the space when I was working in it wasn’t enough. The cold temperatures have an effect in other ways from increasing the moisture content of your wood-pile, through encouraging mould, to making your steel and iron tools to rust.
Tackling the project seems daunting at first and even when you’ve decided on the right approach there is a longer term risk that you might have to repair, replace or remediate issues in the future.
One way of tackling the question of what is best approach is to consult as many insulation manufacturers and refer to their technical documents for installation advice. You need to have a list of success criteria, risks and problems to overcome to help you assess the ‘best’ solution as well.
My List of 8 Requirements
I cannot insulate the outside of the workshop, I must choose an option that minimises the amount of space I loose internally.
My walls are sound and dry; however the bricks sometimes ‘wet-through’ when it rains heavily on windy days.
The roof insulation should be installed into the pitched roof.
I need to be able to paint the walls and mount light objects on them.
I need a system that is flexible enough to work on all the walls and work well around the garage door and personnel door.
The materials need to be good sound insulators.
I will be mostly installing the insulation myself on my own.
My budget is £50 per metre of wall, £250 for the roof-space.
The Rigid PIR Insulation Choice
Having established quickly that rigid PIR insulation board would be the ideal choice for both walls and ceilings I then began to consider how to undertake the installation and where to source the material from.
I found Insulation Express to be a cost-effective source for the insulation and much cheaper than both DIY stores and traditional builders merchants. In addition they offered free deliveries which allowed me to break-up my order into batches with 3 of the 4 deliveries being completely free.
As to the installation options:
ROOF: 50mm insulation to be cut to size and installed between the rafters and taped. Over the top a second 30mm layer to be installed. Between the insulation and the tiles between 35mm and 50mm of space to be left for circulation. Between the two layers of insulation, a 25mm gap.
WALLS: 25mm x 50mm roofing battens to be installed with a damp-proof membrane fixed to the rear of the batten. 40mm of insulation to be installed on top with the finished wall surface being either: a) 12.5mm Plasterboard or b) 12mm MDF.
The products chosen from the Celotex Range were:
Celotex PL4000 40mm + 12.5mm Insulated Plasterboard
Celotex GA4000 Insulation Board 50mm
Celotex TB4000 Insulation Board 40mm & 30mm
12mm MDF from B&Q (UK)
