Weathertight Remediation: An introduction for builders


This is the sixth in a series of articles based on a number of workshops on weathertight remediation for builders which the Ministry of Business, Innovation and Employment – Building and Housing group has been running at centres all over New Zealand.

s builders we are all aware of our many responsibilities on our building sites. But in this article I will be taking a snapshot of some of the additional considerations relating to health and safety on remediation projects. Due to the nature of such work, some hazards are elevated from those encountered on “normal” projects, along with additional ones I, for one, had not considered when first getting into this line of work.

The damp conditions and decaying materials present in many leaky buildings create an ideal environment for moulds and fungi to flourish.
Whilst there are hundreds of such moulds, many are relatively harmless. Unless you have had the mould identified by a laboratory, it is best to assume all moulds are potentially harmful, and to take precautions.

One of the most prevalent and common mould varieties which is associated with adverse health effects is stachybotrys (stacci).
Individuals with chronic exposure to toxins produced by this fungus reported cold and flu symptoms, memory loss, muscle aches, sore throats, diarrhoea, headaches, fatigue, dermatitis, intermittent local hair loss, cancer, and generalised malaise.

The toxins produced by this fungus will suppress, and could destroy, the immune system, affecting the lymphoid tissue and the bone marrow, according to Mold Help 2004.
Pretty eye-popping stuff. So what does that mean for the building occupants, those visiting the site and site staff?
It’s not just an immediate hazard — there are longer-term implications, too. How do we deal with it?

It is the spores of this mould that are the most toxic, as they can contain chemicals called mycotoxins. Ingesting or inhaling these spores is when it is at its most hazardous.
Stacci typically grows on products containing cellulose, such as the paper on plasterboard lining, and wood fibre reinforced cement products in the presence of water.
When this mould is damp it is relatively inert, but when it dries out spores become airborne and, therefore, more hazardous to personnel, and can contaminate other areas of the site.

If you think you have found stacci implement the following:
• Identify: It looks like a green/black soot. Get expert advice to be sure.
• Isolate: Dampen the area, and keep moist.
• Document: For health and safety, variation claim and evidence reasons.
• Remove: Get rid of the contaminated material, and/or use bleach solution only if appropriate. Contain to prevent spread of contaminants.
• Dispose: Allowing contaminated materials to dry out could be hazardous, so wrap in polythene and seal.

Knowing that this is a hazard, what is the appropriate Personal Protective Equipment (PPE) gear? If staff are to wear disposable suits, gloves, masks and goggles whilst handling it, is it good enough just to supply it?
I have witnessed staff cross-contaminating their other equipment as they disrobe their PPE, which led me to set up a disrobing procedure to prevent this happening, and also decide what can be re-used or not.

A well ventilated area should be set up for disrobing PPE, with washing facilities for workers and their PPE.
A sobering conversation with one of my staff who had not worn their required PPE and, therefore, potentially taken stacci spores home to his young family, compelled me to re-evaluate PPE compliance on his site.

In consultation with our staff, we introduced an incentive-based competitive environment, which vastly improved the proper use of PPE and was so successful it was rolled out to our other sites. It’s not just workers who are exposed to stacci and other significant hazards on site. There could potentially be many more visitors on a renovation site than on a new build.
For example, lawyers and experts for both sides of a legal dispute, designers and the council staff will probably be on site more often.
Occupants living in the building require careful H&S consideration, especially on tenanted multi-unit sites.

In reality, how can a builder implement their H&S policy when fire egress paths, emergency lighting, fire rated linings and decks are going to be impacted during works? Has the cost of keeping them safe 24/7 been allowed for in the contract?
There are other hazards that are elevated on such projects and require consideration. One of these is tarpaulin-affected scaffolding. I have seen first hand scaffolding being lifted dangerously in strong winds.

Dust is another, especially from cutting plaster cladding. But by simply using dust extraction equipment on cutting gear, it can be minimised.
Whilst additional H&S risks potentially do exist on these types of projects, they can be easily managed with planning and knowledge.

Wrap Up:
The next article in the series will look at practical considerations when a builder gets to site.

Suggested follow up areas for more information:
• Building and Housing web site:
• Building and Housing publications
• Guide to Remediation Design
• Guide to the Diagnosis of Leaky Buildings
• Dealing with Timber in Leaky Buildings
• OSH Bulletin 17
• ACC Think Safety First kit
• BRANZ February 2013 Guideline: Biocontaminant exposure when remediating leaky buildings

• The author: Harry Dillon has been involved with the repair of more than 300 homes as a builder over the past 10 years. This article represents Mr Dillon’s views which may not necessarily be same as the Department’s.

Previous articleBuilding contracts — some terms to be wary of!
Next articleRisky business