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Cavity insulation condition inspection survey

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    Cavity Wall Insulation
    Condition Inspection Surveys

    If your property didn’t get a proper cavity wall insulation installation, damp problems, damp smells, cold spots, mould, and other tell-tale signs may already be present or be lurking unknown to the house owner and may not show for some time. The damage that can be caused by failed cavity wall insulation can cost thousands of pounds to put right and can seriously affect the value of your house and your home.

    Needless to say, if the cavity wall insulation is compromised or has failed, it will not be effective in providing the advised 33% heating energy savings and if it is wet, it could actually be having the opposite effect and costing you more to heat your home.

    Oscar Onsite can help you identify these issues in a bespoke onsite survey which has been compiled by OSCAR and our Chartered Surveyor partners.

    If you’re living in or intending to buy a property that has cavity wall insulation installed, it’s worth considering the long-term effects on the property and potentially its value. The results may surprise you. It is estimated that up to 6 million of the 17 million houses that have been installed with retro-fit CWI have failed or have faults and can cause damage to the house and will need to be extracted. Oscar Onsite are now working with homeowners and tenants across England & Wales to provide technical assistance in relation to retrofit insulation measures and provide an in-depth technical assessment and survey reporting service. The scale of the Cavity Wall Insulation problem was discussed in Parliament in November 2016.

    Oscar Onsite is the UK’s Leading Authority in Cavity Wall Insulation Surveying and Extraction and their RICS Partners and Chartered Surveyors. They understand the insulation process more than anyone and particularly Cavity Wall Insulation, to identify its current condition, if it has reached the end of its life span or has failed due to a variety of reasons, and identify any areas that have contributed to its failure that should be remediated if you intend to have the latest cavity wall insulation reinstalled.

    A specific Cavity Wall Insulation Condition Inspection Survey involves a visual building inspection and an invasive inspection into the cavities to see exactly what is going on using specialist borescope equipment. It requires an amount of time spent at the property, an in-depth assessment of the building’s performance and identifiable defects and produces a detailed report which is secondary checked to ensure it is 100% accurate.

    The ability to drill into a cavity in multiple locations provides a surveyor with valuable information and photographic evidence as to the performance of the Cavity Wall Insulation and condition of the cavity throughout, identifying problematic issues such as rubble in the cavity or voids. There is a wealth of information a surveyor will collect.

    If you suspect that the performance of the Cavity Wall Insulation may be compromised, the following points should be considered by your surveyor plus many other factors and investigations:

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    Exposure to walls from wind driven rain

    Areas across the UK are zoned into exposure areas of 1, 2, 3 and 4, much depending on wind driven rain. Your home is exposed to severe levels of wind-driven rain if your home is located in an unsheltered position, e.g. not protected by trees or other buildings

    Drill patterns of the installation

    The drill pattern is the tested process that the BBA state in the install license that says CWI should be installed by drilling holes in a recognised pattern to ensure a proper and adequate fill. Any variation from the drill pattern may contribute to CWI failure.

    Size and condition of drill holes

    Drill holes should be a standard size and once the CWI is installed, these holes should be sealed up properly and ensure no water can enter the cavity and into the insulation causing it to get wet.

    Cavity trays and weep holes

    Whichever cavity tray construction is used, weepholes are required. At least two weepholes must be provided to cavity trays above openings and pre-formed “weeps” should always be used at maximum 900mm centres and always be positioned at stop ends.

    Brushing off between properties

    Cavity wall insulation brushes are used as the ideal solution to separate the cavity at the party wall prior to filling with blown cavity wall insulation. This ensures the fill is full and there is no leakage of insulation outside the insulated area or causing trespass to your neighbours’ walls.

    Location of internal dampness, mould and/or condensation

    Where damp is found internally, this is usually the best area to investigate on the outside of the building relative to where the damp is showing.

    Type of insulation

    Three main types of retrofit insulation used across the UK are blown fibre, blown wool and foam.

    Overall wall thickness

    The thickness of a wall and the depth of the cavities also play a big role in assessing a property to see if it is suitable for cavity wall insulation to be installed, and to what amount of insulation is required to achieve the correct thickness and density to gain a proper install.

    Location and condition of damp proof course

    A damp course should be at least 150mm from the ground consistently all around the property. 150mm is usually the height of 3 bricks. If a damp course is less than this, a property might suffer from rising damp which can severely affect the insulation and cause it to get wet and fail.

    Internal temperature and relative humidity

    A good install of cavity wall insulation should also ensure that sufficient ventilation is allowed through wall vents and sub-floor vents. On many occasions, these vents were sealed with silicone meaning the insulation and property cannot breathe. Any moisture ingress cannot escape, and can cause severe problems inside the cavities and inside the property.

    Voids in the insulation

    Voids in insulation mean there are holes of any size in the insulation which can cause warm moist air to meet cold air which can cause condensation, damp spots and mould.

    Spalled brickwork

    Bricks are porous and spalled brickwork where the front of the bricks are damaged and cracked will allow water to penetrate far easier and ultimately allow water to penetrate into the cavities and into the insulation.

    Deteriorated pointing between bricks

    Small hairline cracks in the pointing between bricks can allow water ingress to the cavities and again allow the insulation to get wet and transfer water to the inside of the property.

    Where a surveyor will be able to view the cavity and identify any voids, damp, rubble, sagging or other issues, a judgement can be made on the performance of the Cavity Wall Insulation. With reference to technical documents (e.g., BBA system certificate), the report can give accurate information to assist homeowners and ultimately aim to prevent damage to the property, and the report may suggest the insulation is fully extracted to limit further damage.

    Even where the Cavity Wall Insulation may seem to be performing without any problems, homeowners will often request guidance on living with Cavity Wall Insulation now and in the future, knowing now that so many CWI installs have failed, prevention is better than cure.

    Many conveyancing solicitors now require a copy of any CWI guarantees be held on file as part of the home buying process, given the reported large number of properties that are reported to have CWI failure.

    A sound and proper install of Cavity Wall Insulation into a property that is suitable can achieve the promised 33% heating energy savings, which is a massive saving, year in year out for a 25-year period. Combine that with sound and effective Loft Insulation, and your heating energy savings can be almost halved.

    Frequently Asked Questions

    Who are Oscar Onsite and what can they do to help me with my Cavity Wall Insulation?

    Oscar Onsite are the UK’s Leading Authroity in CWI Surveying & Extraction. We are a UK body that trains independent contractors all across the UK in process, methodology, compliance and all related matters, to ensure these firms deliver quality and exceptional service. With 17 million homes having been installed with cavity wall insulation, and an estimated 5 million needing to be extracted and upgraded with new insulation, and all 17 million having the potential to be removed and replaced over the next 10 years, our work aims to assist industry to deliver the best outcome for homeowners and make their properties dry and warm.

    Why use Oscar Onsite?

    Oscar Onsite are independent of the member firms that will help identify failed CWI and remove it. We have strict rules of compliance for these firms in how they must carry out their work with quality and integrity, ensuring the works are completed to the highest possible standards.

    What is a Cavity Wall Insulation Condition Inspection Survey?

    This survey has been designed bespoke by Oscar Onsite and our partner survey firms who are members of the Royal Institute of Chartered Surveyors, using a combined wealth of specialsit knowledge built into a prescribed survey. A qualified surveyor will attend onsite and carry out a full check of each elevation, from the top to the bottom and make an assessment on all matters such as gutters, downpipes, brickwork, pointing, windows and doors and seals, damp course etc, as well as using specialist equipment to look inside the cavities and see teh real condition of the cavity wall insulation and report on all of these matters.

    How much is the Cavity Wall Insulation Condition Inspection Survey?

    The onsite survey, assessment and report costs just £295.00 including VAT

    Who carried out the Cavity Wall Insulation Condition Inspection Survey?

    A qualified surveyor attends onsite and follows a prescribed survey process and records opinions and collects photographic evidence of each elevation and inside the cavities on each elevation, which is then sent to a Chartered Surveyor to review and provide the report.

    What happens after the survey?

    All of the information and evidence collected is sent to a Chartered Surveyor to review, assess and report on. Where there are matters to note the report will detail these and why they may need attention and where cavity wall insulation is identified to have failed, the report will recommend extraction where applicable.

    What is the Oscar Onsite Cavity Clearance Scheme?

    Oscar Onsite member firms understand the value of their work and understand the process of submitting evidence of their completed works to Oscar Onsite to be checked and verified and to issue a Clearance Certificate where the works are to the required standard.
    Clearance Certificates give the homeowner a formal certificate of complaince to prove the cavities are free of insulation. Clearance Certificates can be submitted to Building Control as cavity wall insulation is a recordable measure, and can also form a part of your homeowner paperwork, for things like insurance policies or when applying to have new insulation installed. It is a secondary robust check to give homeowners ultimate peace of mind.

    Canʼt find what you are looking for? Try our Help & FAQʼs for more information about our Cavity Wall Insulation Condition Surveys.

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    Cavity Wall Insulation Inspection Condition Survey by filling in this quick form.