CompetentRoofer - Frequently Asked Questions

Q: If I use a CompetentRoofer, how will I know that the work complies with Building Regulations?
A: To become a CompetentRoofer, roofing contractors are required to demonstrate their understanding of Building Regulations; members are also kept updated of any changes to the regulations.  By joining the CompetentRoofer Scheme, the contractor has pledged to abide by the Building Regulations and will be subjected to random inspections on his ‘work in progress’ to ensure that standards are being upheld.

On completion of your roofing work you will be issued with a Building Regulations Compliance Certificate by post (direct from the CompetentRoofer administration team); you must keep this certificate in a safe place as it is likely to be required when you come to sell your home.

Q: How is the scheme controlled?
A: CompetentRoofer is licenced by The Department for Communities and Local Government  (CLG) and run by The National Federation of Roofing Contractors Limited (NFRC) Ltd.

Q: Will I get a Warranty?

A: All domestic roof refurbishments up to a value of £50,000 will be automatically issued with a 10 year warranty, Insurance warranties are also available for large, Industrial and commercial projects.

Q: What if I have a problem with work carried out by a CompetentRoofer member?
A: Should you have any problems with the roof following completion of the work we recommend that you contact the roofing contractor first.  Should you fail to achieve a satisfactory outcome, you should contact CompetentRoofer on 0207 448 3189.

Q: My roof needs a structural alteration; can a CompetentRoofer authorise this change?

A: The work should be reported directly through the Building Control department of the Local Authority. It can be registered via CompetentRoofer providing that the structure and loadings are assessed by a qualified structural engineer and their report confirms suitability.

Q: Can a CompetentRoofer replace my rooflight?
A: Yes - CompetentRoofers are able to replace rooflights provided no structural alterations are required.

Q: Can a CompetentRoofer install solar panels on my roof?
A: No - CompetentRoofers cannot ‘self-certify’ on the installation of solar panels.

Q: Can a member of CompetentRoofer convert a flat roof to a pitched roof?
No - this outside the scope of CompetentRoofer. This would need to be notified via Local Authority Building Control as there are structural elements involved (i.e. the pitched element) – unless tapered insulation was used in which case it is still a flat roof.

Q: Is CompetentRoofer a Trade Association?
A: No - A trade association is an organisation which represents the collective interests of an industry, such as roofing.  NFRC is a trade association which represents the roofing industry for example.  The difference between NFRC and CompetentRoofer is that NFRC members would also need to be members of CompetentRoofer in order to self-certify, or, as with any other roofing company, they would need to have the works approved by the relevant Local Authority.

Reportable jobs

Q: I am refurbishing more than 50% of my roof; do I need to inform Building Control?
A: Yes - In most cases, if more than 50% of the roof is being replaced / refurbished Building Control must be informed. If you use an approved CompetentRoofer member they will be able to ‘self-certify’ that the work complies with Building Regulations and you will be issued with a Building Regulations Compliance Certificate and your Local Authority Building Control will be automatically notified. If you do not use a CompetentRoofer then a Building Control inspector must inspect the work to ensure that it meets Building Regulations in order for you to receive a compliance certificate.

Q: If I am carrying out roofing refurbishment work but the insulation does not need upgrading, is it still reportable?
A: Yes - if 50% or more of the roof is being replaced/refurbished then in most cases Building Control must be informed.

Q: Are garage roofs reportable?
A: No - unless the garage is heated (with fixed heating, not portable heaters). 
Q: Which flat roofing projects are reportable?
A: All domestic dwelling or commercial/industrial flat roofing jobs are reportable if over 50% of the roof is being refurbished i.e. the roof covering is stripped and there is a thermal element.

Q: If a flat roof has no insulation requirement (i.e. has no fixed heating nor is a dwelling), is it reportable?
A: If a flat roof is not being insulated because there is no ‘thermal element’ i.e. the area below the roof has no form of heating (or cooling i.e. cold store), such as a garage, then the work is not reportable.  However, if it is not being insulated because of technical or economic (i.e. payback less than cost) reason then it is reportable.

Q: Will a change in the weight of the roof coverings require a structural survey?
A: For most roofing types an increase or decrease in load of 15% is considered acceptable before a structural survey is deemed necessary.  An increase or decrease of more than 15% will require a structural survey.

Q: Can a roofing refurbishment job for a Grade 2 listed building be registered through CompetentRoofer?
A: Yes - providing 50% or more of the roof is being refurbished.

Q: Does CompetentRoofer cover work on property within a conservation area?
A: Yes - all buildings in general need to comply with the requirements of the Building Regulations.

CompetentRoofer members are authorised to replace the roof covering of a roof and for associated works – the main impact on the Building Regulations is Part L – Energy conservation, and possibly Part A – structure.

In respect of properties in a conservation area or properties subject to listed building status they will need to comply with those two regulations. The main restriction conservation area status has on the work is to do with a building’s appearance i.e. that the replacement roof covering would need to be sanctioned by a planning approval i.e. the client would need to apply for planning approval – even if the original roof covering was taken off and the same slates / tiles reinstated.

It is possible that installing extra insulation to meet the current building regulations would affect the outward appearance of a property; in that case there would be dispensations to allow a reduced level of performance that does not compromise appearance.

In short, CompetentRoofer members can do work that they are authorised to do in a conservation area provided they that they have been tested for the appropriate heritage skills that may be required in that conservation area, e.g. Kent peg tiles, stone tiling, random slating etc.

Q: Is roofing refurbishment work on a conservatory roof reportable?
A: If the doors between the lounge and conservatory still exist then there is no need to upgrade the insulation in the conservatory roof.  However, if the doors have been removed i.e. the lounge and conservatory become interlinked then they must upgrade the insulation as the heat from the lounge will pass into the conservatory and out through the roof (and walls).

Q: I am refurbishing a roof where only 50% of it is a thermal element; is this work reportable?
A: Yes if any part of the roof acts as a thermal element, then refurbishment work is notifiable to the LABC.

Q: I am replacing slates with clay tiles on a roof.  Can this work be reported via CompetentRoofer?
A: This depends on the weight of the slates and the weight of the clay tiles.  If the clay tiles represent an increase in load upon the structure of more than 15% then the work should be reported directly through the Building Control department of the Local Authority.  It can be registered via CompetentRoofer providing that the structure and loadings are assessed by a qualified structural engineer and their report confirms suitability.


Q: What is the minimum insulation that should be in a roof to meet the minimum U-value of 0.35WmK threshold value? 
A: Roughly 140-150mm for “quilt” type insulation and 75-80mm for rigid board type insulation depending on material/manufacturer.
Q: What is the thickness of insulation that will give a U-value of 0.18W/m2K?
A: Roughly 270mm for quilt type insulation and 120mm for rigid board insulation depending on material/manufacturer.

Q: What is a ‘cold roof’?
A: For a pitched roof, it means insulation is placed between the ceiling joists.  For a flat roof, it means insulation is placed between the roof joists, with cross-ventilation between the insulation and the deck.  For flat roofs in particular, it can be a costly method of retrofitting insulation due to the work required. If not done correctly and with adequate ventilation, it can lead to problems with condensation.

Q: What is a ‘warm roof’?
A: For a pitched roof, it means insulation is placed at rafter level.  For a flat roof, it means that insulation is placed between the supporting deck and the waterproof outer layer.  This is the recommended method for flat roofs.

Pitched roofs

Q: When stripping an old roof and the existing roof is close boarded, is there a requirement to upgrade the insulation underneath?
A: If the total U-value including the existing insulation does not meet the threshold requirements of Part L of the Building Regulations (i.e. U=0.35), then yes the insulation will need to be upgraded.

Q: The roof refurbishment job I'm looking at involves a loft which has been converted into a room, and the rafters have been covered over with plasterboard.  Do I need to remove some boarding to look at the insulation thickness and assess the U-values?

A: Yes - you must know if the existing insulation meets the threshold value of 0.35 U-value, i.e. about 150mm of quilt. If it does then well and good – if not then the roof should be insulated to 0.16 – which will mean stripping the boards filling between the rafters with extra over the top and then counter–battens and battens to ensure airspace under the underlay.

Of course it may not be technically possible to do this because you will raise the roof finished level; in that case you will have to leave the insulation and boarding as it is.  If they do not have an air and vapour control layer (AVCL) between the plasterboard and the insulation then there may be a possibility of condensation occurring if more insulation is added.

Q: If a house has a fully boarded loft with insulation between the ceiling joists, can extra insulation be added over the boards if required to top up?
A: Yes - extra insulation can be applied over the boards – but ensure of course that ventilation is not blocked at the eaves.


Flat roofs

Q: For flat roofs when the timber deck is not being replaced, is there a requirement to upgrade the insulation underneath?
A: If the total U-value including the existing insulation does not meet the requirements of Part L of the Building Regulations, then yes the insulation will need to be upgraded if technically and economically possible.

Q: A flat roof needs to be refurbished; if the waterproofing is replaced what is the minimum thickness of insulation required?
A: Approximately120mm of rigid board.

Q: I am NOT stripping the waterproofing off a flat roof – do I need to upgrade the insulation? 
A: No - if you are simply overlaying with new waterproofing leaving the existing waterproofing in pace then this is a repair not refurbishment and upgrading the insulation is not required. Additionally, this job doesn’t need to go through CompetentRoofer as it is not reportable work.

Q: How do I install or upgrade insulation if the material is not a good fit, bearing in mind that insulation material becomes more expensive depending on how thin it is?
A: Insulation should only be installed or upgraded where it is technically practical and economically viable (payback on energy costs saved over 15 years).  Whatever insulation is used, the roof must also be ventilated enough to avoid condensation.  If it is not technically possible to install full insulation, for instance it would affect threshold heights then it would be expected that any insulation would be installed which does not adversely affect the existing building.

Q: A flat roof that is a thermal element (separation of hot and cold space) needs to be refurbished and I don’t know how much insulation there is in the void between the ceiling and the roof.  What should I do?
The extent of the insulation must be determined to see if it meets the requirements of the Building Regulations.  Any insulation is unlikely to meet the minimum standard if it is between the roof joists i.e. a ‘cold roof’ and so the contractor will need to address this.  The contractor will usually create a ‘warm roof’ by removing insulation, sealing any ventilation, applying a vapour control layer (VCL) to the deck, adding insulation to the top of the roof and then applying new waterproofing.

Churches and graded/listed buildings 

Q: When refurbishing a church roof – does the insulation need upgrading?
A: Churches i.e. the place of worship are outside the requirements of Part L of the Building Regulations so would not; however church offices, halls, meeting rooms etc are included and would need insulation brought up to scratch if below the threshold.

Q: I am stripping and replacing the tiles on a Victorian church hall. There is about 100mm of insulation in the roof space, must the insulation be upgraded; the church has very little funds?

A: Unfortunately yes, unless the roof was the actual church i.e. a place of worship it must be upgraded to current standards.

Q: I am tendering to strip and re-slate a Grade II listed building. I intend to use Spanish slate rather than Welsh slate like the original. Am I allowed to do this and do I need to upgrade the insulation?
A: The first part of the question is a planning not building regulations issue.  Change to the appearance of a listed building should be checked with the planning department of the local council and English Heritage.

As regards insulation most historic or listed buildings will still need to comply with building regulations and upgrading the insulation is likely, however the work must not prejudice the character of the building or cause degradation of the fabric by using inappropriate materials or design.

The fabric of historic buildings function differently to modern construction and this must be taken into consideration. It may be possible to get an exemption from applying the full requirement of Part L if the technical demands are proven.

Building Regulations

Q: For a roof over a block of flats does each flat have to have a Building Regulations Compliance Certificate (BRCC)?
A: Yes - each flat within the building will need to be registered. Even if they are not directly under the roof, as the roof and it's function (i.e. weather protection / thermal efficiency) is serving the whole building.

Q: I’ve seen a roofing contractor not abiding by Building Regulations; can I do anything about this?
A: Yes - if you suspect that a roofing contractor may be breaking the law by not complying with Building Regulations you may anonymously report them by calling 0207 448 3189 or click to display.


Q: I've lost my Building Regulations Compliance Certificate, can I get a new one?
A: Yes - you can apply for another copy of the Certificate (which you will need when you come to sell your home) but there will be a charge of £10.  In order to update the current list of FAQ's on the CompetentRoofer website, we have collected some of the questions which have recently been raised and the answers given by our Technical Manager.

Q: What happens if I ignore the Building Regulations?
A: The building owner would not get a compliance certificate for the work carried out and this will affect the sale of the property as the fact will be shown in solicitors’ searches.  Solicitors will carry out these searches in order to prevent the risk of claims made against their own professional indemnity insurance should defects be found which only became apparent after the sale of the property.

There is also the risk of prosecution; under Section 35 of the Building Act, any persons not abiding by the Building Regulations faces a fine of up to £5,000.  Additionally, if the work is found not to be compliant with the Building Regulations, then the building owner may be compelled to have the work put right.

We get questions on a regular basis, so keep your eye out on the CompetentRoofer website for more FAQ’s and answers.  Please scroll down to find questions on the scheme, reportable jobs, insulation and Building Regulations.

For further information or advice please call us on 0207 448 3189.