05.Dont get ripped off
With all insulation, there should be no gaps except around hot objects such as downlighting and gas flues. Any such gaps are called heat bridges and decrease the overall efficiency of the insulation. Experts advise you to get into the roof yourself after your insulation has been installed and check the job has been done properly. The exception is when you've had loose fill installed that's higher than the ceiling joists.
Loose fill - settling
Loose fill can settle over time, so you need to ensure you get what you pay for.
- Talk to your installer - if they claim it won't settle, ask for a written guarantee.
- If they admit to a certain amount of settling you can ask for the installation of more material to compensate. For instance, if the R-value is achieved at a depth of 100 mm, they may install 110 mm. However, this may mean the material will cover the ceiling joists (the usual joist height is 100 mm) until it settles. This could make walking around the roof dangerous.
- The other option is to ask for a top-up in, say, six to 12 months' time.
A job poorly done?
- If you find that an insulation job has been poorly or incompletely done, you're not obliged to pay until problems have been rectified.
- Go to your state's department of fair trading or building regulatory bodies if you're unhappy with the work done.
The most commonly self-installed materials are batts. You'll find installation instructions on the packaging or the manufacturer's literature.
When installing rockwool or glasswool batts these materials can cause itching and respiratory irritation, so you must wear:
- Long-sleeved shirt
- Closed shoes
In fact you should really wear protective clothing when installing any insulation to avoid respiratory irritation from dust in the roof space.