Posted By jervis
Have you took in to consideration about the asbestos risk assessments etc sounds more important. I not to sure but if general public are below then would netting be needed for safety reasons!

Posted By ian_f
I would take a look at HSE's guide INDG284 'Working on Roofs'; should give you the answers you're looking for.

Posted By Robert K Lewis
The major problem in this type of job is the amount of dust that can fall into the building as the ventilation can be rather restricted. I have to admit that I prefer to use scaffold towers/scaffolds for this type of work but it does depend on the precise site layout.

Remember that netting is actually strictly a fall arrest system and is concerned with reducing fall height to a minimum, thus should be fixed immediately to the underside of the roof steel. It is however one step above harnesses. Just as important is the sequencing of work and if one is to replace with a non fragile material then the removal and replacement can move in tandem, thus resticting the areas requiring protection.

Bob

Posted By jervis
Little concerned getting a lot advice on the netting but part of question was the repair of an ASBESTOS roof have you looked at ways of reducing the risk to this!

Posted By Iolo Roberts
This is not going to answer much but may provoke thoughts leading to solutions.

ASBESTOS would be my first concern. Licenced removal/disposal and dust control being high on the list of considerations. You certainly wouldn't want to drop an asbestos-cement roof sheet as the dust released would be most unwelcome! However, if it fell into a debris net, how do you deal with that? Also, will the repair method generate any dust? If yes, what protection is there for the workers and those around? How will the dust be recovered & disposed?

No excuse for dropped objects these days, particularly people. Crawling boards & harnesses make me ask questions:

How will this method avoid asbestos debris dropping from the roof? What I have in mind is a weak roof sheet failing under pressure from crawling board. It seems a risk that could lead to an asbestos release.

Harness: What is it clipped to and how is it assessed as adequate to hold a fall? What is the rescue plan? How will the fall occur? If through an asbestos sheet then we are back to uncontrolled release of asbestos.

As we are dealing with asbestos cement sheets, debris netting should be a last resort. Netting to save a falling worker is admitting all alternatives are impracticable and still needs a rescue plan.

Can the work be done from a cherry-picker? Non-contact method apart from point of repair.

Is the extent of the damage or method of repair likely to cause the damaged roofsheet to fall? If so, access from underneath and build an 'asbestos tent' style box to catch the debris should the roofsheet collpase. This then gives you some control over the asbestos. An asbestos licenced scaffolding company would be able to advise.

Yes, that asbestos stuff is a headache!

If it was a tin roof I'd still be looking to a cherry-picker approach.

Posted By Robert K Lewis
Repairs to ACM roof - famous last words - "It is just a small patch repair". Repairs tend to grow as the material breaks in a different position. Most of these roofs are now 10+ years old and are becoming increasingly brittle with age, even crawl boards can cause damage especially if you do not strip back the full strip from eaves to ridge. Some systems such as decadex and scrim do work but their use is limited. One has to look at the economics of attempting parch repairs.

Bob

Posted By db
It's difficult to give a general guidance without knowing the full facts but Netting certainly would be integral and although it doesn't prevent a fall it is COLLECTIVE protection rather than personal protection.

The problem with crawl boards is that someone has to climb up and put them in place and move them around from place to place at which point they'll probably have no protection.

Call your local HSE office and see what response you get. My bet is they'll say use nets.