I work for a housing association and we need to carry out an inspection and repairs to a tower block roof where we also have a number of mobile phone masts. I have struggled to find some easy to follow guidance on how we manage this and whether it is safe to work on the roof for a short duration i.e. for the inspection or if the masts need to be turned off when any person is present on the roof. All the information I can find so far is so technical that I will probably need a degree in physics to make any sense of it as it depends on the type of aerial it is and the level of Hz, distance etc. Coordinating with the Mobile phone companies for an outage is a nightmare and took nearly three months to arrange an outage previously, the more companies involved the more difficlut it is and there are three companies involved. The roof leak is quite bad and we have had to move a tenant out so we would like to proceed quickly. There was a post on this subject before and I have P.M'ed the originator but not had a reply. So is there anyone out there who has encountered this before. Any help gratefully appreciated. Kind regards Lisa

Lisa, Would it be worth contacting some of the large contractors who specialise in this type of work? (eg Balfour Beatty). They routinely erect new masts/repair existing ones and may be willing to share info on the required precautions. Rgds. John

You will need to liaise wiyth all the dish/transmitter owners as there are various types of transmitter and the safe zones will need to be individually checked as even markings do wear out or become illegible. Depending on the repair location you may not need a shut down but the comapnies do need to be involved. I have been out of this type of work a few years and calculations are complex - without knowledge of precise kit you cannot work anything out. Bob

Lisa It's my understanding from various sources, including an HSE specialist inspector who gave a presentation some years ago to the inimitable IOSH Public Services Section for Manchester and the North West, that the signals transmitted by mobile phone mast antennae go out directly from them towards and slightly below the horizon. Therefore, unless the antennae are located in low positions with accessible roof surfaces directly in front of them, people carrying out inspection and repair work on such roofs are probably not at risk. By contrast, engineers trained and authorised to carry out maintenance or repair work on such antennae are at risk and therefore have to follow specific procedures e.g. locking off the power to an antenna before gaining access to it. Pester the operator/s of the mast/s involved for clarification about the extent of the risk areas in front of them. Also, people living or working in a building below antennae for mobile phones and other purposes are not at risk. In fact, contrary to widely held and entrenched misperceptions about mobile phone masts, people directly below them are not exposed to their signals. This is because the signals go out at right angles from the antennae in what might be described as a narrow band which gradually gets deeper (and loses strength!) with increasing distance from the antennae. The signals cannot droop or bend down into any building below and immediate surrounding areas. Unfortunately, most people see and unquestioningly believe media stories about campaigns against mobile phone masts in local neighbourhoods, including baseless assertions about the health risks from them. Thus, it's not surprising that anxiety about masts gets needlessly reinforced and perpetuated. I'm no expert on this topic. My comments reflect the standard advice I developed some years ago for my former employer especially in regard to queries and concerns about mobile phone masts near its schools. Among other things it was founded on advice from the UK Health Protection Agency (HPA) and also a report about 10 years ago by (Doctor or Professor?) Stephen Barton an expert from Manchester University. Among other things he explained (logically in my view) that having lots of mobile phone masts would, contrary to popular misperceptions, reduce exposure to mobile phone signals. The greatest exposure occurs to people if and when they use mobile phones rather than simply being in the vicinities of masts. If phones are used in an area with few masts, they have to operate with greater signal strengths than in an area with lots of masts. (as an aside, presumably phones which have to work with high signal strengths also consume battery power more quickly.) As the greatest exposure to signals occurs when mobile phones are held by users close to their heads or other parts of their bodies, this seems to underline the advice given some years ago by the Stewart Report that the use of mobile phones by young children (i.e. with rapidly developing brains) should be kept to a minimum and perhaps even avoided. I'm relying on memory here as I don't currently have ready access to my notes with details about the Stewart Report, etc.

Hi Just pulling the plug will not work because the transmitter will be backed by UPS or battery, Also Mobile phone sectors are directional but is that all that is on the roof what about di pole antenna ? They will be a risk of damaged or broken feeder cable .

Really ? There's usually a switch on the cabinet that performs that function.....and the feeder will be a solid copper outer.....so not much chance of accidental breakage. There's much more risk if the unit has a parabolic antenna for the links.....in which case the erp can be a kilowatt or more....

Thank you to all who have replied so far. For additional information there are 3 x OLO Polemounted antenna and dishes, 3 x H3G antenna, 4 x OPCS antenna, 2 x OMNI antenna and 1 airwave. (Macrocells) We have been told we are unlikely to be granted permission for an outage until after the Olympics because of the police use and so we need to know if there is a 'safe' time for a surveyor to be up there without them being turned off so we can find out what the roof condition is like, and also if we can then get a roofing contractor in to carry out some temporary repairs until the outage can be arranged for September as the leak is getting worse. It is this 'short term duration' I would like some guidance on. Any help appreciated. Lisa

Hi Lisa, Generally you can work up to 2 metres of the face of antennas, your landlord should be able to provide classification and working arrangements for the particular rooftop. The operators are reasonable and if you state there are emergency repairs to be carried on the roof, they should be able to power down sites if works are required in close proximity to antennas/omnis. I have some operators landlord guidance I can send to you if you PM your email address to me.