Asbestos Roof Problems Discover your options at

Asbestos Roof Problems Discover your options at

Asbestos roofs are still very common in the UK as it’s estimated by the UK’s Land Registry, that more than 75% of those ever installed are still in service today.

That says a lot about the strength and quality of the material, but the original predicted life span was only 40-50 years.

Given that the majority of asbestos roofs were installed in the 1960’s and 1970’s, many reaching the end of their planned economic and useful life and will need replacing.

However, the lifespan does depend on a number of factors, including geographical location, maintenance, etc. as we’ve seen plenty that were installed in the 1930’s and are still pretty much as good now as they were when they were installed.

The truth of the matter though, especially on larger industrial properties, is that roofs are not particularly well maintained and probably only receive any attention when they begin leaking.

At which point, most companies perform patch repairs of varying quality, but these can only ever be considered temporary.

When repeated attention to an asbestos roof is required, it’s time to consider a more permanent solution.

The Options

Patch Repairs these are localised repairs to fix specific problems. As a roof ages and starts to deteriorate, leaks begin to appear around roof lights, fixings and gutters.

When a reactive maintenance approach is taken, the immediate problems are often solved with temporary repairs using materials like torch-on sealants, silicons, fabric, paints and self-adhesive tapes.

Though effective, such repairs usually fail relatively quickly and continuing attention will almost certainly be necessary.

Cleaning & Coating Larger asbestos roofs on industrial and commercial buildings can sometimes be cleaned and coated to prolong the life of the roof.

In such cases, the entire roof is usually treated in one application. Most asbestos roof coatings are guaranteed by the manufacturers or installers and some will be insurance-backed, though care must be taken in your choice of contractor, because unless the manufacturers instructions are followed completely, your guarantee will not be valid.

As building surveyors with considerable experience with asbestos roofs, we recommend cleaning and coating a roof only in limited circumstances, depending on whether you own the property or you are leasing it and for how long.

This is because once a roof deteriorates to the point that it requires coating, it is likely to suffer further deterioration.

Most older asbestos roofs suffer some degree of de-lamination of the asbestos cement roof sheets. Once there is evidence of water ingress to the actual panels (rather than through holes in the roof itself), water can become trapped within barely visible fissures.

In extremely cold conditions, the water freezes and the fissures expand, breaking the surface of the asbestos cement sheet away, taking the coating with it in most cases.

Even a rubberised or other flexible coating will not necessarily protect from this happening and we have seen many examples where coated roofs have broken down in this way. It should be pointed out that it usually the failure of somebody to spot the existence of fissures in the sheets that leads to this problem, which is why an independent roof survey is strongly recommended before contemplating this type of repair it could save you tens of thousands of Pounds.

Over-cladding - Asbestos roofs can sometimes be over-clad with metal profile sheets, leaving the original roof in place.

Using a frame system, the metal sheets are laid directly over the roof and in most cases, additional insulation is also provided between the two roof surfaces.

At the same time as over-cladding a roof in this way, it is good practice to also renew roof lights, since they are relatively inexpensive and will let in far more light than old ones, which tend to break down, discolour and become brittle after being in place for many years.

Over-cladding an asbestos roof could provide you with a longer-term solution than some coating systems and it is usually cheaper than replacing the existing roof. However, there are a few things to take into consideration.

First of all, the structure of the property has to be considered. These days, industrial and commercial buildings are made to pretty precise calculations, with everything being done by computer to take into account the loadings that will be placed up the building, taking into account the additional weight of snow for example.

Back in the days when asbestos roofs were being installed, this was not the case. A structural engineer would carry out manual calculations for supporting steels and then add in some tolerances.

This was actually a good thing, since the structural steels were more likely to be over-specified, meaning that they probably would take the additional weight of an over-cladding system. But, that isnt always the case.

We recommend therefore, as part of the due-diligence process, that the structure is examined by a structural engineer prior to commencing such a project.

Other things to consider are that over-roofing still leaves an old asbestos roof in place. Additionally, the height of the building will change, which will almost certainly require planning permission from the local authority before works can commence.

Re-Roofing - If you are looking for a fool-proof method of stopping leaks, a new roof is always the answer. Its also the most costly solution. New modern roof sheets generally comprise a twin wall metal roof panel with varying degrees of insulation contained within.

Ever-changing energy performance targets set by the government mean that the thickness of the insulation is always changing, but all panels supplied these days will be compliant with current building regulations. The cost is the major consideration, since changing an asbestos roof is very expensive and there are no short-cuts.

Costs are increased when the roof is double-skinned, since you are doubling the quantity and cost of disposing of the asbestos.

Heath & Safety Issues

Asbestos Roof Problems Discover your options at

All roofing work is dangerous, but asbestos roofs have their own unique set of difficulties and consequently, a significant element of cost, no matter what solution you choose, is going to be in this area. There are various elements of costs.

The major one will be the scaffolding and access system tens of thousands of pounds can be spent here. Next comes the internal netting. In most cases, especially where people are working beneath, a double netting system will need to be employed to prevent people, tools and debris from falling into the space beneath.

There are no cheap short cuts. Scissor lifts or cherry pickers will need to be hired and in some cases, walkie-talkies used to allow communication between the workers on the ground and those on the roof.

Given that these costs will be incurred anyway, it is worth considering the most long-term solution right at the start, because with many coating systems, it is almost certain that you will spending money replacing your roof, or re-coating (if possible) in ten years time. A new roof will usually give you around 25 years life expectancy.

Proposed Legislative Changes

The Control of Asbestos Regulations 2006 specifies which asbestos works are licensed. Asbestos roofing work is not licensed and therefore can be carried out by any competent roofing firm, though many are reluctant to work on asbestos roofing projects.

The Health & Safety Executive in England has now introduced a new classification called Notifiable Non-Licensed Work (NNLW).

This new category involves online notification, has no fee implication and it is very unlikely that the works will be inspected by the HSE. Unlike normally licensed asbestos works, there is no requirement for 14 day notice periods, so work can commence immediately.

Though there is not normally a requirement to notify asbestos roof works, it is good practice to notify since this avoids all criticism and only takes a few moments.

Why use A Surveyor?

As experienced Building Surveyors, we will give you an unbiased and professional opinion based on many years experience in this very specialised area.

Our roof report will provide you with options and budget costs based on your own unique circumstances and once delivered, we can help you with the decision making process and then manage the entire project from start to finish, including helping you decide on the right contractor to use, by running a competitive tendering process on your behalf.

Our management fee is charged as a percentage of the value of the works, but typically, we save our clients considerably more than this, both in terms of financial savings and of course, the peace of mind in knowing that the job has been completed correctly in accordance with the manufacturers guarantee requirements, as well as looking after all health and safety requirements and where necessary, HSE notification.

To discuss your asbestos roof issues on industrial or commercial property, please call us on 0121 711 7110 .

Theres no obligation, just friendly and free initial advice from real asbestos roofing experts.

Chartered Building Surveyors


Leave a Reply