Prior to undertaking a job we often receive a property report from the surveyor’s inspection.
Here is a brief extract of the type of information and recommendations we receive.
The spray foam consists of isocyanate and polyol resin which react with each other when mixed together and expand up to thirty times its original size as it dries. It is applied by spraying to the material that is to be insulated.
Damage
The drying action of the foam can cause the foam to expand into small voids and gaps which can result in lifting of tiles.
During our inspection we did not observe any lifting of tiles.
When the foam encapsulates rafters or tile battens (when there is no underlay) it can effectively trap damp into the timbers. This will cause rot to develop over time.
During our inspection we did not observe any rot to the timbers, but it must be noted that only a small area was opened up and the risk exists that there are areas of rot to the timbers that are currently concealed from view.
The insulation has been applied between the rafters. This is the incorrect location for loft insulation which should be installed between the ceiling joists. Installing the insulation between the rafters encourages more moisture laden air to enter the roof space from the rooms below, potentially adding to the long term risk of rot occurring. In addition to this, providing the insulation at high level only serves to heat the loft space, a complete waste of energy and resources, causing the home owner to pay more for their heating, not less.
Recommendations
The spray foam installation does not appear to have caused any structural defects. As such we recommend the insulation is removed by hand and the retained underlay and rafters etc are clean.
In the event that any rot to timbers, or further defects are uncovered during the cleaning works, we are that in the first instance the damage is photographed and emailed to us.
Spray Foam Issues
Although spray foam insulation applications have been common over the past few years, they are often installed without any consideration to other elements of the building such as fire risk, ventilation etc.
Some of the more common issues are highlighted below.
Mortgages and Lending
Many mortgage providers will not lend on properties that have had a spray foam insulation instal carried out. This includes mortgages for sales, mortgaging, and equity release loans. Unfortunately, when it is commonly known that lenders will refuse mortgages for a specific reason, it is considered that the property has a value of zero. This will not affect sales to cash buyers, but they may well be aware of the same issues, in which case a substantial reduction in the asking price may be sought.
Electrics
All too often, spray foam is applied over live cables serving the property. If designed correctly, this may not be an issue, but it is the cabling that needs to be appropriately designed, and not the foam. Electrical cables produce a nominal amount of heat when in use and this is not normally an issue as the heat can disperse. Encasing a cable in spray foam can reduce the cables’ ability to disperse heat and can result in overheating of the cables, leading to a potential increased fire risk.
The latest edition of the wiring regulations – the 18th Edition sees an increase in cable sizes when cabling is surrounded in insulation. Such works are seldom undertaken to a property when installing this type of insulation.
