Rubber Reroof

Mid-Winter 2011 we were asked to inspect this old Butynol roof on a block of 4 single story residential units which was leaking.
Over the last few years a variety of other roofing contractors had undertaken repairs to some sections of the roof, but the bottom line is that at 30 years old the roof has reached the end of its serviceable life.
At some point contractors had stripped in a cover/ detail tape over the original joints in the Butynol, and coated the black 1mm rubber with Aluminium Paint, which probably added another 10 years life to the roof.
hover cursor over image for text, click on them for larger version

Roof 1

roof area over front entry view over main part of the roof other end of the roof closer view of gable end reverse view of main roof area

We gave the owner several options for re roofing the area, new 15mm plywood and 1mm or 1.5mm Butynol, or re use the existing substrate and 1.5mm Butynol, Grey or Black. The old substrate was quite springy so we were not happy with just 1mm membrane in that situation. To re-use the existing substrate it would have to be rescrewed and the existing nails punched down and then sanded off all over.

In the end he chose the cheaper re-use existing substrate option, but with the 1.5mm Grey Butynol, which would help reduce the heat soak and keep the inside cooler in the Summer.
The first task on taking possession of the job site was to temporarily remove the bottom row of concrete tiles so that the new membrane could be dressed up underneath.
Also at the two walls the bottom weatherboard was removed, for the same reason.
2 layers of building paper was put in where the tiles and weatherboards came out, just in case of a shower of rain that night. It did, and then winds of 90kmph over the weekend and then the coldest day in 16 years. No water passed into the house below during the storm.


the bottom row of tiles removed building paper temporary cover weatherboard being removed, east end weatherboard being removed, west end east end temporarily secured  west end temporarily secured

After that storm passed through the next step was to repair spongey areas with new plywood. The 1/2″ chipboard had survived remarkably well over the 30 years and the recent leaks only resulted in some minor sagging and damp patches in the wood. These areas had to be cut out and repaired and it was better to do this as a seperate task rather than have to do it when each section of roof was torn off

Substrate Repairs

small section of chipboard cut out a sagged section, rubber cut out one of the main leaks cut out cut out sagged section cut out sagged section cut out sagged section repairs sealed up for overnight repairs sealed up for overnight

New Rubber Membrane

old rubber removed and new screws added gordie sanding the substrate installing the new rubber first section done, sealed to old overnight 2nd section ready to lay first sheet half adhered gluing the sheet same area wet from dew the next day 3rd section 3rd section re screwed and sanded skylight and join to old roof west end rubber completed


almost done heat resistant hot pipe collar cold pipe collar tiles back in metal flashing to wall same area as first picture

Roof 2

Two months later the owner of the adjoining unit asked us to re roof their roof.
This section had only leaked around one of the the outlets, and the substrate generally appeared in reasonable condition with just some sheets that had sprung up due to nail head rusting, causing ponding water.
Same specification as the earlier roof, re-screw, punch old nails down, sand, silicone taped joints and 1.5mm Dove Grey Butynol.
As it happened the weather in September was worse than in the Winter, with drizzly and showery conditions every second day. The first strip torn up was quite small because of the risk of rain.
I had two different helpers on this job, as it did drag out (because of the bad weather), Slavko from Slovenia and Tamba from Sierra Leone.


part two some major patching been done here blank serious ponding in this corner view along the tile transition

The Re-Roofing

low section against wall and outlet replaced same area, drizzle in the hills coming in overnight seal onto old with seam tape in between Slavko peeling up next strip of old rubber same at the other end two and a half strips replaced there lapped onto old not quite half way laying new membrane at other low siderubber down, blue skies two strips to go overlap to old, with tape between

After a week of rain and wind, a restart on the last central section. No leaks during the storm, thanks to seam taping the temporary overlaps onto the old rubber.
Tamba blowing off dust after sanding last two strips are in one complete roof re-mortared barge tiles and outlet looking across from first section replaced tile and re-mortared barge tiles that ugly corner now that pipe is a bit close to the tiles a sacrificial piece of rubber is glued to the pipe to reduce abrasion
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