The maximum performance of foam board insulation depends heavily on proper installation. Therefore, it’s best to have a certified insulation installer do it. If you’d like to have it installed professionally, you should do the following:
- * Obtain written cost estimates from several contractors for the R-value you need. Don’t be surprised to find quoted prices for a given R-value installation to vary by more than a factor of two.
* Ask contractors about their air-sealing services and costs as well, if needed.
To evaluate batt installation, you can measure batt thickness and check for gaps between batts.