Property clinic: What is involved in removing asbestos?

Our property experts answer your DIY queries

Loft conversions: It is vital to ensure that there is free air circulation throughout the loft void including the various interfaces. Photograph: Getty Images
Loft conversions: It is vital to ensure that there is free air circulation throughout the loft void including the various interfaces. Photograph: Getty Images

Q I own a 372sq m (4,000sq ft) renovated listed building (circa 1880) in Dublin 4, which is let as four own-door offices. I am considering converting two of the office units into one residence for my own use. What is the process for getting change of use from offices to residential? What are the implications for Dublin city rates? Do these disappear for the residential part of the building? And does local property tax (LPT) then apply to just that part of the building? What other issues need to be considered?

A The good news is that the planners are generally in favour of returning period buildings to their original residential use, although their preference is usually to have the property returned to single use rather than multiple units or split between residential and commercial use as you propose. Check out the Dublin City Development Plan.

It is advisable to engage a conservation architect for any works on a listed building. Your architect will have the experience required to prepare a planning application and to deal with the various conservation, accessibility and other issues that will arise. The Irish Georgian Society may also be of assistance.

Your chartered surveyor can deal with the rates. Effectively the part you convert to residential will no longer be liable for commercial rates, but there is a formal revision process to go through. The residential part of the property will then be liable for LPT, water charges etc.

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Residential use has a higher fire risk than office use. Occupants are more likely to cook and sleep at home than in the office, so you will need to consider the insurance implications. A building surveyor will also be able to advise you on building regulations.

Simon Stokes is chairman of the Residential Agency Professional Group of the Society of Chartered Surveyors Ireland (SCSI)

Asbestos removal

Q I am in the process of buying a 2,000sq ft bungalow which I believe was built in the 1950s. A survey of the house has indicated that there may be asbestos in the roof. Given the health risks associated with asbestos I am anxious to have it removed. I will soon be exchanging contracts and I would like to know before I do, what is involved in removing asbestos and if it is a tedious and expensive process. Is it something I could get rid of quite easily once I have moved in or should I back out of the sale?

A Asbestos is a naturally occurring fibrous mineral popularised in the 1950s for construction due to its fire-proofing and insulating qualities. It was manufactured in many forms some more dangerous than others. The serious negative effect on health caused by inhaling some types of asbestos fibres was realised in the 1980s and it was finally banned in 2000. If you find asbestos in any condition don’t take any chances, leave it alone and seek professional advice.

It should not be disturbed and it is illegal to dispose of the material unless you have a licence with a registered disposal facility. Deciding what to do will depend on the level of risk and cost. Both depend on what type of material is present and where it is. In some cases asbestos may be retained – so long as it is sealed and clearly identified as a hazard to prevent future disturbance or risk.

Your report indicates there ‘may’ be asbestos in the roof area. The most usual material used in roofs would have been asbestos cement slate or sheet which is relatively less dangerous than either pipe, loose or quilt loft insulation which I would not normally expect to see in a domestic roof built at that time.

The cost of removal of some particularly hazardous types of asbestos can be considerable. Your surveyor was possibly not able or qualified to positively identify the suspect substance so you should ask them to obtain positive identification and advise further on the material. He may need specialist advice or an invasive investigation might be required which will require the cooperation of the vendor. Alternatively, you might ask the vendor or their agent to investigate on the basis that you may not be able to proceed as the risk is unknown. If the vendor is not prepared to cooperate then you possibly should withdraw from the purchase.

If your surveyor obtains the necessary identification then they will be able to advise you what implications and costs might be associated or if removal is necessary and what the risk is. You should then be able to make a judgment regarding how to proceed.

Fergus Merriman is a chartered building surveyor and a member of the Society of Chartered Surveyors Ireland (SCSI) Building Surveying Professional Group.

Loft condensation

Q We have recently moved into a house. We soon discovered that there was condensation on the walls of the loft which I assume has been recently converted. Upon further inspection I noticed that there was an absence of insulation behind the loft walls. How can I remedy this issue?

ATypical loft conversions comprise low walls under sloping roofs set inboard from the outer eaves. These are generally timber stud and plasterboard with insulation between the studs. They join with the upper slope to form sloping ceilings with plasterboard underneath timber rafters which should also have insulation between. Horizontal timber cross ties, form the ceiling level and these are insulated with a thick mineral fibre quilt. A quilt is also used in the void between the base of the low wall and the outer eaves over the ceiling of the room beneath. The omission of insulated construction will permit heat loss to the void areas and consequently condensation will form, as seems to be the case in your situation.

It is easier to form the insulated construction at the outset, but rather more difficult to fit afterwards. If safe working access is unavailable then apertures should be formed to fit rigid insulation boards behind the low walls, to fit tightly between the timber studs. Ensure there is continuity with the mineral fibre quilt above the ceiling of the room beneath.

Where the low walls meet the sloping rafters above, it should be practical to fit rigid insulation board between the rafters towards the higher ceiling level. Insulation of mineral fibre over the loft ceiling should be straightforward with suitable access. Continuity of insulation is important at all interfaces of vertical, sloping and horizontal parts of the roof loft void.

It is vital to ensure that there is free air circulation throughout the loft void including the various interfaces as described. Ensure there is 50mm between the insulation and the roofing felt over, to allow air flow which will dissipate any condensation that can form under the roofing felt. You may need to insert slate vents either side if there is insufficient venting provisions.

The aforementioned is the most economical method. There are spray foam applications but these would need checking to ensure any installation does not block air circulation throughout. I would advise the assistance of a chartered building surveyor to guide you through the installation process and type of insulation and venting necessary.

Jim Drew is a chartered building surveyor and a member of the Society of Chartered Surveyors Ireland (SCSI)

Send your queries to propertyquestions@irishtimes.com or to Property Clinic, The Irish Times, 24-28 Tara Street, Dublin 2. This column is a readers’ service. Advice given is general and individual advice should always be sought