Do you know what is good gutter installation? More to the point does the building industry know about Good Gutter Installation?

Like my observations in my last blog post in respect of incorrect roof sheet installation we often see in our building inspections gutters installed other than as required by the Building Code of Australia and the accompanying Australian Standard covering gutter installation, AS/NZS 3500.3:2003.

We are often finding gutters during building inspections with inappropriate fall and with gutters joined incorrectly. This follows on from the overlapping observations of roofing materials in that blog.

So what is good gutter installation?

The Building Code of Australia in clause P2.2.1 specifies that a drainage system must convey surface water to an appropriate outfall and avoid surface water damaging the building. Under clause 3.5.2.4 it indicates that as a means of achieving this the gutters must have a minimal fall of 1:500 and installed on brackets not less than 1.2 metres centres.

It references the Australian Standard AS/NZ@ 3500.3:2003 which repeats this call. This standard in turn requires a number of other requirements to ensure good gutter installation.

Of interest is the assumption under clause 3.2 that the design of gutters assumes regular inspection and cleaning and under clause 3.5.1 that they shall be designed so that water will not flow back into the building. How many home owners regularly clean their gutters? Do you?

With the assumption they will be maintained when in all probably they won’t be, one would hope that our contractors would provide good gutter installation. Yes!

Don’t assume they do.

I reckon 80% of home or building inspections of pre-owned homes would show minimal if any gutter fall in the direction of the downpipe. We often indeed see gutters falling the wrong way and therefore holding water. Unfortunately we see this too on new builds.

Gutter falling wrong way

Gutter falling wrong way

Digital level shows gutter fall to right

Digital level shows gutter fall to right

 

 

 

 

 

 

 

 

 

Gutter full of water

Gutter full of water

Clause 4.5.1 indicates there shall be no restrictions to the free flow of stormwater due to protrusions or other obstructions or debris eg. cement, mortar, clippings and similar.

Finally clause 4.13.2.1 indicates soldered joints shall be clean and free from grease, and shall be flush and lapped in the direction of the outlets. Clause 14.1.3.2.2 requires where using sealant that laps shall be as for soldered joints.

All too often we see gutters in our building inspections filled with building debris including roofing screws not used, metal cuttings and swarf. Not only will this material potentially cause early corrosion in the gutter the serve to restrict the flow of water which is direct contravention of the Code’s requirement.

All too often in our home inspections  we also see the gutter overlap in the opposite direction to the outlet.

Overlap of this gutter running opposite to direction of water flow.

Overlap of this gutter running opposite to direction of water flow.

Often enough for us to wonder if the roof installation industry is aware of the Code and the Standard. Often enough for us to wonder how much supervision is focused on the installation of the roof.

All the more reason to employ an independent and reliable home inspector.