future simple passive: roof

Showing posts with label roof. Show all posts

16 Jun 2014

The roofing membrane is laid - we are now watertight!

I had lined up our contractors, GSPR, a good while ago to apply the single ply membrane to our roof. They came highly recommended by one of our design team. Then our schedule slipped and unfortunately clashed with another of their jobs. The heavens also decided that they would add further to the delays by sending down pouring rain on the days when work should have started. Inside the house, water was soaking through and the boards that had been laid as sub-flooring were pretty saturated, with pools growing ever larger on the concrete floor below. At last the stars aligned and the GSPR guys were able to begin.

The first job on site was to dry the external OSB on to which the membrane was to be bonded. Large and small flame-blowers were put to work. Once the surface was dry the membrane could be rolled out and bonded. We are using Ruvitex single ply system. My father is very doubting about flat roof systems in principle but we have been reassured that the technology has advanced leaps and bounds since the 70's & 80's. This product comes with a 20yr warranty.

A few fiddly details; the guttering vents, ventilation stacks & roof lights. It was also decided by the contractors, once on site, that we would need an additional product applied to guarantee watertightness- an aluminium edging strip that will ensure that no water can get behind the membrane on the parapet upstands. An additional cost, but it's got to be done, shame it wasn't in the initial estimate.

There has been an issue with the membrane not bonding to the rooflight upstands, so Andrew is going to make some ply sleeves for the membrane to adhere to.

Look a small puddle of water...should I be worried? When it rains the water gushes out and down, so this is what gathers when the rain has stopped. It will evaporate, it's not massive...?!?

A return trip is due next week to finish the rooflight upstands and the gutter vent detailing. Typically now that we are watertight, the rain stopped and the sun shone!

1 Jun 2014

The roof lights arrive

I am so pleased with our new roof lights. So beautiful.

It's such a shame that I won't often get to see the beautiful frames. But everytime I look up at them from the inside I will know how gorgeous they look on the roof! I've become such a geek during this building milarky, you are so involved with every detail big and small.

The guys at Roof-maker couldn't have been more helpful. They arrived as scheduled and Andrew and Paul installed them within a blink of the eye.

Just as well they were so quick to install as the weather has decided not to play ball and the downpours arrived and just kept coming. You'll hear all about that in the next post. But earlier in the week when the weather was better Andrew and Paul were continuing with linings and perforations through the roof.

It's been a fitful couple of weeks all said.

16 May 2014

Building up the roof

We will have a flat roof, this is a cost-driven design choice. Roof trusses and slates cost a whole load of extra money. Early in the design process it was a butterfly roof but it eventually became flatter. If we are honest, this was not our first choice from a practical basis - we get a lot of rain and having it run down a steep pitch is just common sense. However it suited the design of the building and we have been reassured that materials have improved massively to make flat-roofs a safer bet nowadays.

In order to deal efficiently with water runoff, the roof has been designed to slope gently to the centre, and then slope to the outer edges where there are downpipes. There was a lot of last minute phonecalls between CLD and Andrew where the tension between cost and pitch were debated. With a smaller pitch the furring strips (a tapered batten) can be cut from a single piece with both sides being used. As the pitch increased each strip would have to be cut from a single piece, doubling the cost. In the end cost was the winner, I'm sure the water will move effectively down and off the roof!

The parapet

The openings for the rooflights have been built and this means that the measurements could be passed to Roof-maker, so that they could manufacture to the exact internal measurements. Andrew and Paul made them to precisely to the exact mm. So retrospectively we could have put the order in earlier, as there is now a few weeks wait before they are delivered. The rooflights will be fitted and then the Single Ply membrane installed. At that point we will be weather-tight (except maybe for the parapet capping)!

Another development was resolving how the utilities, which currently terminate in 'The Hub', were going to be ducted into the house. As we were perforating the building there was a lot of air-tightness and insulation issues to address. The ducting has been done now and eventually the electricity, gas, water & telephone will be pulled through.

With the building somewhat, although not entirely, impervious to rain, the Upper floor was boarded out, which meant that we could walk around upstairs for the first time (I was not a joist-hopper like Andrew and Paul).

Cracking on!

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