You would hope that most people had wised up to this way of saving maybe £300 per year in energy bills but there’s still large numbers of older properties sold which haven’t had insulation installed in the loft and cavity walls.
This is something you can do yourself but you’ll need to be diligent about it – a bad job here can lead to serious damp issues further down the line as badly-installed insulation can simply act as a wick for moisture. At least when you hire a professional you’ll get a guarantee to call on – and if you opt to use certain materials, you’d be unwise not to get a competent person to sort it for you.
When you buy a new place, it’s always worth getting a home buyers survey: bear in mind that your mortgage valuation survey won’t normally involve a surveyor actually entering your property and poking around in the loft (if accessible). And your RICS surveyor, who is acting purely on your behalf, can give you a professional opinion on whether insulation is present and what condition it’s in as well as noting any suspicions of property defects. Their report is particularly valuable to your solicitor as part of the conveyancing process generally.
Cavity wall insulation material choices
- Mineral wool/rockwool – these materials are the speediest to install and the most value-for-money but the flipside is the shorter lifespan of effectiveness.
- Polystyrene Beads – these’ll cost you more to install and getting a professional involved is recommended. Get the fitting wrong and damp can eventually invade via the gaps in the material.
- Foam – here, we’re talking about either polyurethane or urea formaldehyde foam. Once again, you should get a professional to install it. It’s very insulating, although eventually it breaks down which decreases its effectiveness.
Loft insulation material choices
- Blown-fibre – you should hire a professional contractor for this. They use a machine to blow fibre insulation into the gaps between joists. The process is quick and very handy if a loft is difficult to access but it’s probably the most expensive choice.
- Batt or blanket – you can easily install this material yourself, which consists of either mineral, glass or rock fibre or foil-backed felt, and works best when you can easily access loft spaces. You should be particularly careful to wear protective gear when handling material like glass fibre however, because it is a particularly nasty skin irritant.
- Loose-fill – you can also look to install this material yourself, which normally consists of cork, mineral wool, cellulose fibre or recycled newspaper. You should use protective equipment and clothing to install it and there is some risk that materials will loosen, lowering their effectiveness, if you’ve got a particularly draughty loft.
- Sheet – this consists of firm sheets which are fire and moisture resistant and they come into their own if you have to tackle insulating a roof’s sloping side. The material is relatively expensive.
What’s the cost of fitting effective loft and cavity wall insulation?
You can expect to pay perhaps £300 and upwards to insulate the loft of an average 3-bedroom semi-detached home. Naturally if you opt for more expensive materials and involve professionals, you’ll have to budget for perhaps a few hundred pounds more.
Are there any Government schemes which might help?
Happily, yes! You should visit the Government’s online Green Deal Energy Saving Measures page – https://www.gov.uk/green-deal-energy-saving-measures – and additionally, there are a number of websites devoted to promoting free insulation which the Government pays for, such as https://www.freeinsulationgrants.co.uk/, but you should always check your eligibility and any scheme’s terms and conditions.