Doing something is not always better than doing nothing at all
With rising energy costs and the desire to reduce greenhouse gas emissions, many homeowners are considering wall insulation upgrades to improve energy efficiency and comfort in their home.
It is important to understand that different homes require different retrofit upgrade solutions
Therefore the following are key considerations before embarking on solid wall insulation retrofit:
1) What is the condition of the wall; what materials have been used in the construction e.g. brick, stone, concrete
2) You will need to address key junctions: window reveals, joist ends, soffits, soil pipes, floors
3) The Vapour Open “Breathable” option. What is a breathable material? The term ‘breathable’ is used loosely and means different things to different people. To avoid confusion for a material to be breathable it must have the following characteristics:
- Vapour Permeable – it has the ability to allow vapour to pass through
- Hygroscopic – it has the ability to absorb moisture
- Capillarity Active – it has the ability to release absorbed water through it pores or capillaries In addition to having the materials used in the system breathable, all the component parts of the wall to be insulated must be breathable also.
4) The Vapour Tight Internal Wall Insulation optionVapour tight systems are the most common solution used in the market today, usually in the form of insulated plaster board.
Considering a “non-breathable” wall cannot cope naturally with the movement of water, then the following 5 critical factors MUST to be present in an Internal Wall Insulation (IWI) system to make sure it’s “DESIGNED” performance is equal to it’s “INSTALLED” performance.
Continuous Vapour Control Layer
Continuous Insulation Layer – No thermal breaks
Thermal Bridging due to multiple fixings
Thermal Looping due an unventilated cavity
Adequate treatment of thermal bridging – reveals, returns & floors
5) Cold Bridging at key junctions must be adequately addressed to optimise the overall retrofit upgrade
The effects of not dealing with thermal bridging
Whatever system you choose, vapour open or closed, the materials may change but it is important that the detail at key junctions should remain unchanged.
One important message to keep in mind when considering a wall insulation upgrade:
“Understand the consequences of your actions before applying an insulation upgrade onto solid walls irrespective of the materials you use”
Liam Brown – Enviroform Solutions
Enviroform provide tailored insulation solutions for new builds, retrofits and the most complex heritage property restorations.