Spray Foam Insulation & Building Surveyors

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Spray Foam Insulation For Building Surveyors – Introduction

Let’s face it: some spray foam insulation installations are non-compliant, have been poorly installed or may have been installed in the wrong environment. There wouldn’t be stigma or mortgage issues had every legacy installation been perfect. The spray foam industry should acknowledge the imperfections of some of these legacy installations and that they may not be in accordance with the 2021 issue of standard BS 5250. Likewise, there have been many instances where an entirely compliant installation has been rendered unsuitable from a surveyor’s perspective and their reports may reference the presence of spray foam as negative or potentially damaging to the property.

We’ve seen cases in which spray foam insulation has been applied to low-resistance, breathable roof membranes in new builds only for the building surveyor to render the installation as likely to “rot the roof” despite the product certification stating this is a compliant and acceptable application. Perhaps this is down to a lack of knowledge on the material or a lack of available information at the point of survey. We must find a way to move past the stigma and opinions so that the homeowner does not become the victim of unnecessary spray foam removal if it’s technically compliant or can be made compliant.

Through industry engagement, scientific assessments, the creation of best practices, updated guidance, better training and the demand for higher standards, the spray foam industry is changing and building trust with homeowners, surveyors and mortgage lenders. New technologies can take time to become mainstream solutions, and during their initial implementation and use, flaws or imperfections can occur and may require some effort and patience from industry stakeholders to iron them out. When a working group formed to produce the Inspection Protocol, this updated guidance was supposed to help building surveyors and lenders to assess spray foam insulation. Despite this, the stigma and concerns regarding spray foam insulation continue to cause distress and hardship on homeowners.

A terrace of existing, 1940's built, UK homes where spray foam pitched roof insulation may have been used to bring the insulation levels up to modern standards. A terrace of existing, 1940’s built, UK homes where spray foam pitched roof insulation may have been used to bring the insulation levels up to modern standards.

The Building Surveyor’s Role

Whenever a homeowner decides to sell their property, the prospective buyers and their mortgage lenders will generally appoint a qualified building surveyor to conduct a condition survey. Many areas of the property will be assessed, and part of the survey will identify defects or risks that may damage the structural stability. The roof is a significant area that protects the internal integrity of the property, and when roofs leak, or their structure is weak, this can severely impact the property’s value.

Building Surveyors make assumptions based on what they can see during the inspection. In an ideal world, every structural element of the building would be visible during the survey. However, this isn’t realistic, considering that measures such as pitched roof insulation and loft conversions are acceptable practices. The next best thing is for the building surveyor to have access to paperwork and information that might help them consider risk profiles based on methodology, design, and implementation. It will still be possible for building surveyors to assess the roof’s condition from an external assessment. Depending on the findings, they should be able to conclude whether the roof is weathertight and free from leaks or moisture ingress.

A Building Surveyor considers risks and then communicates their findings to the prospective buyer and mortgage lender. Realistically, they can only comment upon what they see and the information in front of them. Unless there is evidence to support the condition of a structural element they can’t fully assess, they should pass a comment to the prospective buyer and mortgage lender that they cannot arrive at a suitable conclusion. It then becomes a matter of discretion for the lender to decide whether to offer a mortgage to the buyer or to appoint further professional inspection. 

From time to time, Building Surveyors may express a negative opinion about the presence of spray foam insulation without having full access to the facts, paperwork and evidence that supports the installation. Whilst this can be frustrating, it is generally not their fault as their opinions will likely be formed on having encountered some non-compliant installations in the past. Nonetheless, at the point of the survey, unless there is evidence that supports a negative opinion, the only comment they could and should offer is that they cannot arrive at an informed conclusion and pass the case back to the prospective buyer or mortgage lender to consider further evaluation. 

Modern low-resistance and breathable roof membrane where spray foam insulation can be spray-applied directly as per its BBA or KIWA certification. This is classed as low-risk installation. Modern low-resistance and breathable roof membrane where spray foam insulation can be spray-applied directly as per its BBA or KIWA certification. If there is evidence to show that the spray foam has been applied directly to a low-resistance roof membrane, this should be classed as low-risk installation and a Building Surveyor and mortgage lender should support it as a compliant.

Spray Foam Assessments & Conclusions

A building surveyor can assess and formulate an opinion on a loft conversion or pitched roof insulation in many ways, even if the internal elements are concealed or inaccessible.

External Roof Assessment:

An external roof assessment is usually carried out during a building survey. Building Surveyors will have different ways of assessing the roof’s condition. Still, generally, using a pole camera or even a drone, it is possible to check the roof to identify the following:

  • Are the roof tiles aligned and in good condition without any visible cracks or slippages?
  • Is there a chimney, and is the lead flashing around the chimney/roof junction in good condition?
  • Are ridge tiles present, aligned and in good condition?
  • Are there roof valleys where roof pitches join, and are they in good condition?

If the answer to the above questions is YES, the roof is likely not leaking; therefore, the pitched roof insulation is unlikely to be saturated with water content. Communicating with the current homeowner can also be a proactive step. Asking about any repairs or renewals could determine the age of the roof and the likely type and condition of the roofing membrane under the tiles.

Broken and damaged pitched roof tiles that may become an entry point for wind damage, driving rain, frost and snow which can damage the roof structure. Broken pitched roof tiles that may become an entry point for wind damage, driving rain, frost and snow which can damage the roof structure.

Internal Assessment:

The internal assessment of the roof condition is likely to be compromised when the loft is converted; sloping ceilings are covered by plasterboard, and pitched roof insulation has been installed. It is important to note that pitched roof insulation doesn’t just come in spray foam insulation; it can also be mineral wool batts, PIR board, or multi-foil insulation, which will conceal and cover the roof membrane and timber structure.

There are several reasons why a Building Surveyor may not be able to comment on the condition of the roof based on an internal inspection, which includes:

  • The roofing membrane and its condition are not visible due to loft conversion or pitched roof insulation concealing the space.
  • No paperwork that supports the survey, design or installation of a loft conversion or pitched roof insulation.
  • Potential knowledge gaps on the pitched roof insulation and its performance.
  • No evidence of a condensation risk analysis to support the risk profile of the installation.

Certain checks can be carried out irrespective of the loft conversion or insulation concealing the roof structure, which includes:

  • Is the plasterboard or insulation in good condition and free from damp, mould, and staining?
  • Does the insulation appear dry to the touch, and are there any obvious signs of watermarks on the plasterboard or insulation?
  • Is there any evidence of water leaks or drips on the attic floor?
  • Where any structural timbers are visible, what is their moisture content?
  • Is the insulation hermetically sealed, rafter to rafter, without breaks, gaps or penetrations?
  • Does the property have applicable ventilation in bathrooms, utilities and kitchens? If so, the risk of interstitial condensation is likely to be low.
  • If closed-cell spray foam insulation has been used, is the surface smooth, or is it possible to identify ridges where roofing battens are located? This could determine a direct-to-roof tile application that would be deemed high risk.
  • Does the homeowner know who installed the insulation? If spray foam insulation is used, it may be possible to identify the installation company and likely brand of spray foam insulation used.

Following these checks, without sight or confirmation that the installation has been conducted compliantly, the Building Surveyor should record their findings and present their report to the prospective buyer and mortgage lender. A more invasive survey could be recommended before concluding whether the pitched roof insulation poses a risk to the property. 

The tell tale signs that closed cell spray foam insulation has been applied directly to roof tiles. The horizontal lines within each rafter bay are the roofing battens which hold the tiles in place. The tell tale signs that closed cell spray foam insulation has been applied directly to roof tiles. The horizontal lines within each rafter bay are the roofing battens which hold the tiles in place. This would be deemed a high-risk installation that a lender is unlikely to issue a mortgage on.

Further Assessments of Spray Foam

Assuming the pitched roof has spray foam insulation but no supporting paperwork or evidence to support the installation as being compliant, an invasive survey can be used to assess its quality and suitability. An invasive survey could comprise of:

  • Small quantities of the spray foam insulation are removed from a rafter bay on each roof elevation. We recommend a horizontal strip around 200-300mm high. The insulation should be removed in this section to expose the roof membrane and provide visibility of the inner faces of the two rafters onto which the foam has been applied.
  • Once removed, it will be possible to identify whether the roofing membrane is a high-resistance bitumen felt or a low-resistance breathable membrane. Generally, high-resistance felts are dark in colour and rigid to the touch. Low-resistance membranes are usually light in colour and paper-thin to the touch.
  • Analyse the insulation. Can it be squeezed and compressed to wring out any moisture? If no moisture is present during winter, the insulation is unlikely to have ever impacted the roof structure. If the insulation is wet during the summer, it will likely have held excess moisture during the winter, and remedial actions will be required.
  • Moisture readings should be conducted across the rafters, exposed roofing membrane and inner faces. The moisture content should be below 20%. In winter, the moisture content may be on the upper end of the scale, and if a high-resistance roofing felt is used, it may exceed the 20% threshold due to moisture accumulation in the outer 1cm layer of the insulation. This does not require removing the spray foam, as a Vapour Control Layer can be fitted on the underside.
  • Analyse the conditions of the roof rafters. Are there any visible signs of wet or dry rot? Are there any signs of woodworm? Even if the moisture content is higher than expected, depending on the time of year, summertime drying will usually eliminate any withheld moisture. Provided there are no signs of timber decay, the solution will likely require a Vapour Control Layer that should be fitted in the summer months once the roof assembly has had time to dry out.
  • Upon completion of an invasive survey and assuming the spray foam insulation can be made compliant without removal, it is essential that any removed spray foam is resealed using a like-for-like product. This can be achieved with portable spray foam packs or by re-mobilising a professional rig.

The big questions are who can undertake an invasive survey and how the insulation will be resealed once partially removed. This is where the spray foam industry could assist. ThermoFoam offers a new service to homeowners, building surveyors, and mortgage lenders who want to see more of the roof structure to satisfy themselves that the spray foam hasn’t or won’t cause damage.

A small section of the spray foam insulation is removed to expose the roof membrane. This will determine the risk profile of the installation and may identify remedials works that should be undertaken. A small section of the spray foam insulation is removed to expose the roof membrane. This will determine the risk profile of the installation and may identify remedial works that should be undertaken.

Moisture readings are recorded to establish whether the pitched roof insulation system is subject to excess moisture that breaches the thresholds where it could cause decay of structural timber. It is also important to establish the moisture content at the membrane in the outer 1cm of the insulation. Moisture readings are recorded to establish whether the pitched roof insulation system is subject to excess moisture that breaches the thresholds where it could cause decay of structural timber. It is also important to establish the moisture content at the membrane in the outer 1cm of the insulation.

How We Can Help with Spray Foam assessments

Perhaps homeowners and Building Surveyors have encountered negative news articles about the spray foam industry and feel we need to be more approachable and helpful. The original installer may no longer be in business and maybe uncontactable. Alternatively, the Building Surveyor may have encountered poor workmanship, which has dented their confidence in spray foam and those who supply and install it. The fact is, despite some media reports, every manufacturer and distributor is approachable and many of the spray foam installers in the industry are professional, diligent and compliant. The industry has moved on over the last few years, and every day, we implement change, refine protocols, and improve how spray foam insulation is installed. We can help building surveyors, mortgage lenders, and homeowners in numerous ways, especially when invasive surveys are required.

To be clear, it is not the role of a Building Surveyor to carry out an invasive inspection on what is known as a Level 2 property survey. This requires a different type of survey from a suitably qualified surveyor. Even when using a surveyor specialising in structural surveys, removing and replacing the spray foam insulation requires specialist kit and may need support from the spray foam industry. To resolve the ambiguity surrounding the suitability of spray foam insulation, it should be assessed on a case-by-case basis with an open mind. Because a Building Surveyor can’t see enough evidence to arrive at a risk rating for the structure, it shouldn’t mean the homeowner is put into a position where they are advised it may need to be removed or that it’s causing damage to the roof.  If Homeowners, Building Surveyors and Mortgage Lenders are prepared to work with us, our service would involve:

  • We organise a visit to the property.
  • We remove a few small areas of spray foam, particularly on each roof elevation.
  • We assess the type of roof membrane and spray foam variant used.
  • We measure moisture content within the exposed timber rafters, membrane and spray foam.
  • We check for evidence of dry or wet rot and timber degradation, including woodworm.
  • We record photographic and video evidence of the roof’s condition.
  • We reseal any removed areas of spray foam to maintain its effectiveness.
  • We produce and issue a full report of findings to the homeowner, building surveyor and mortgage lender.

The Spray Foam Industry is undergoing reform and promoting better practices. Some legacy installations may not meet the required standards that follow product certification, building regulations or BS5250, mainly because there was a lack of regulation in a new industry that was in its infancy. Many new standards and best practice frameworks are already in place, and current and future installations are being conducted in a compliant manner that meets the conditions of product certification and BS 5250. We want to work with Building Surveyors to support them when they encounter spray foam insulation and need help and guidance. Likewise, building surveyors should feel they have somewhere to go for professional advice when assessing spray foam insulation, particularly if they cannot determine whether the installation is low, medium, or high risk.

Whatever opinions have been formulated about spray foam insulation, the stigma surrounding the mortgage problem doesn’t need to be as big as it has become. Remember that lenders want to lend, and several will offer a mortgage when the property has spray foam. Spray foam insulation is often misconstrued as a product that “will” cause damage to roofs, but the fact is that most installations are compliant or can be made compliant to meet compliance with BS 5250:2021 standards. The mortgage lender will often request more information from the homeowner so that they can make informed decisions; therefore, unless the spray foam insulation has been applied directly to the roof tile, all other installations should be assessed correctly, with the removal of the spray foam the very last resort.

The April 2024 Government HSE report provided further clarity about the potential risk profiles of spray foam insulation when used in different climate zones of the UK. This report is a valuable tool for building surveyors, mortgage lenders, and the spray foam industry to determine whether legacy installations are compliant or need remedial works or even removal.

Hygrothermal modelling is used on a case-by-case basis to establish the risk of timber decay. Vapour control layers can be used to change the risk profile to low provided they are installed when the moisture content is likely to be at its lowest. Hygrothermal modelling is used on a case-by-case basis to establish the risk of timber decay. Vapour control layers can be used to change the risk profile to low provided they are installed when the moisture content is likely to be at its lowest. When the insulation system shows a water content of less than 20kg/m3, the risk of timber decay is very low.

The risk of timber decay can be established when hygrothermal modelling is based upon the actual circumstances. Low-resistance roof membranes, ventilated cavities above the insulation and vapour control layers can all contribute to a low-risk profile. The risk of timber decay can be established when hygrothermal modelling is based upon the actual circumstances. Low-resistance roof membranes, ventilated cavities above the insulation and vapour control layers can all contribute to a low-risk profile. 

Important Things To Remember about spray foam

When assessing the condition of a pitched roof during a property survey, it is essential to put preconceptions aside and remember the following:

  • Pitched roof insulation is approved under PAS 2035 and a Building Regulations compliant measure.
  • The homeowner may have invested several thousand pounds in the spray foam insulation. They don’t need to be told it’s useless, may rot the roof rafters, or may need to be removed until it has been thoroughly assessed.
  • The homeowner doesn’t need to be advised that mineral wool insulation on the loft floor may have been cheaper and more effective. There are many types of insulation material available to the homeowner, and there are many benefits to insulating at pitched roof level; these include:
  • Pitched roof insulation can significantly reduce solar gain and alleviate internal temperatures.
  • The loft may be used for storage. Cold roof systems can cause belongings to become damp and mouldy.
  • There may be cold water storage in the loft. Pitched roof insulation can help maintain temperatures and stop freezing.
  • The homeowner may have a solar PV system with inverters and batteries in the loft. Pitched roof insulation can help to maintain ambient temperatures year round.
  • The homeowner may access the loft regularly. Mineral wool on the loft floor can inhibit safe access (if un-boarded).
  • Mineral wool insulation can hold dust and create a home for pests and rodents. Some homeowners may have allergies to dust, whilst rodent droppings are unhygienic.
  • Provided the roof contains a low-resistance membrane or is ventilated above the insulation where high-resistance membranes are present, a warm roof can eliminate the battle between hot and cold. It’s important to remember that insulation slows heat loss; it doesn’t prevent it.
  • Mineral wool insulation can be impacted by wind washing, and it isn’t airtight, which means airflow may pass through it, particularly when it’s become old or has shrunk, slumped or degraded.
  • If occupants use the loft for storage, this can impact the effectiveness of the insulation across the floor area. It can be accidentally moved or compressed, mainly where the loft floor is un-boarded.
  • The presence of spray foam insulation doesn’t mean there is a risk to the roof structure. The spray foam may have been applied to a low-resistance roofing membrane and may be deemed a low-risk installation. Unless there are obvious defects, no conclusion should be made until it has been possible to retrieve and assess paperwork related to the spray foam.
  • Several lenders are prepared to offer a mortgage against a property with installed spray foam insulation. Without apparent defects or flaws in the insulation design and implementation, building surveyors should remain impartial in their comments to the homeowner.
  • Most brands of spray foam insulation installed in the UK have BBA or KIWA certification, which shows their suitability for use in various circumstances. Provided the spray foam has been installed following its certification, building surveyors should not remain impartial in their opinions of the product.
  • It is essential to remember that unless the spray foam insulation has been applied directly to the tile system as a roof stabilisation, it can almost always be made compliant, provided the structural roof timbers are not damaged.
  • It is essential to remember that even if the spray foam requires remedial action to alter its risk status, depending on its age, it is unlikely to have caused significant damage to the structural roof timbers. If damage were to occur, it would manifest over an extensive timescale and almost always not be instantaneous.

Not only is pitched roof insulation an approved measure under PAS2035 and Building Regulations, there might be numerous reasons why pitched roof insulation is beneficial such as the location of temperature sensitive plant and machinery located in the loft. Not only is pitched roof insulation an approved measure under PAS2035 and Building Regulations, there might be numerous reasons why pitched roof insulation is beneficial such as the location of temperature sensitive plant and machinery located in the loft.

 Water tank storage is often located in the loft and could freeze over in colder winter temperatures. Loft and pitched roof insulation is not a one size fits all approach. Homeowners require choice when they are considering upgrading the insulation levels. Water tank storage is often located in the loft and could freeze over in colder winter temperatures. Loft and pitched roof insulation is not a one size fits all approach. Homeowners require choice when they are considering upgrading the insulation levels.

Our Advice For Homeowners, Building Surveyors and Mortgage Lenders

If you have spray foam insulation in your home or are a building surveyor or mortgage lender considering its suitability for the property, gathering information and making balanced judgements is essential. Before any conclusions can be drawn, several steps can be considered:

  • Check that a homeowner pack of paperwork is available. The homeowner pack comprises of:
  • Product details and certification.
  • A manufacturer’s product warranty.
  • An installer workmanship warranty.
  • A condensation risk analysis/hygrothermal assessment.
  • In some instances, a pre-install survey report may be available.
  • If the homeowner knows that closed cell spray foam has been used as a roof stabilisation system sprayed directly onto the tile, a mortgage lender is unlikely to support this application. Once the lender confirms this is required, the homeowner should source quotes to remove the spray foam.
  • Assuming the spray foam insulation appears free from problems, with no shrinkage, de-lamination from roof rafters, apparent moisture content, or evidence that exposed roof timbers are experiencing rot, woodworm, or degradation, there’s a strong chance it can remain in situ. 
  • Where a homeowner document pack is unavailable, we recommend that the homeowner contact the company who installed the spray foam and request copies of the information above.
  • If the company is unresponsive but the homeowner knows the brand of spray foam insulation used, contact the product manufacturer or distributor to request paperwork or assistance.
  • Assuming the installation company is no longer in business, and the spray foam brand is unknown, we can help with an independent assessment to check the quality of the installation. Checks might include removing some of the spray foam in small sections to determine the roof membrane type, moisture content of the spray foam, and surrounding structural timber before resealing it to its original state. A report will be produced along with accompanying photos/videos.
  • Where the installation is not fully compliant or has been applied to a high-resistance roofing membrane, a Vapour Control Layer applied to the underside of the spray foam could be considered a remedial action to reduce future risks to the low category.
  • If the spray foam insulation is not hermetically sealed from rafter to rafter, this could present a risk area where air could penetrate the roof membrane. We recommend resealing imperfections to ensure the spray foam meets an airtight standard.
  • View the removal of spray foam insulation as a last resort and aim to find evidence that the installation meets compliance or identify proactive steps that could bring it up to compliance. Remember, suggesting removal is likely to cost the homeowner several thousands of pounds.

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