Up on the Roof

Since last week's blog progress has been slow but steady. The roof is quite involved and various references have been made back to the timber frame manufacturer and the strucural engineer during the course of the week. To an extent it appears to be over-engineered (but I'm only a surveyor!) We employed a structural engineer to undertake much of the design as this was meant to save time with the timber frame manufacturer; I'm not sure this has been achieved and certainly the cost seems to be a good chunk higher. If we did this again we would handle this aspect differently but 'it is what it is'. The gloom of some dreich November days don't help and I'm beginning to hate the small cold caravan bathroom!!

Turning Chillier

As Steve's previous blog mentions the first floor is in place and in response to Jane's query on keeping the water out you can see the blue sheeting which is keeping the worst of the rain out. Even so I don't think we're getting as much rain as usual for this time of year .....famous last words?!

Portal frame arrives

Late afternoon yesterday saw the arrival of the prefabricated portal frames along with the brackets and bits to put them together. These are more than a week overdue and their late arrival has meant a temporary stop on site for a few days as nothing further could be done without them beyond the ground floor panels which are now in place .
However, things moved along again today as our main builder/project manager and two joiners started to the erect this steel framework into the gound floor panels. By the end of the day two of the three frames were in place and secured.
So why a portal frame? Well, this 1.5 storey house is very open plan internally with generous internal room heights (2.7m ground floor, 3.5m kitchen/diner, 2.9m first floor) such that the upper floor ceilings follow the roof line almost to the ridge, with a small loft space around 1.5m high. With this internal design it was tricky to use a (more conventional) truss system, so the portal frame is used to provide torsional stiffness to the building and carry a roof ridge beam, against which rafters will be supported for the roof. In effect, this is a contemporary take on a traditional method of roof construction.
In designing the roof we have also avoided the use of roof purlins (horizontal rafter supports) by using timber 'I-beams', each of which will span around 5m from eaves to ridge at a 45 deg. pitch and carry the weight of the slate roof supported only at either end. This not only keeps the internal structure clean and uncluttered, but their 352mm depth will be fully filled with insulation and their thin shear web minimises thermal bridging. The end result is a stiff, clean, super-insulated roof structure.
The down side to this constrcution has been additional labour/time and ultimately cost, but the end result should be worthwhile.

Daily Changes

The two joiners erected much of the ground floor on Monday and Tuesday which has been really exciting. Its terrific to see the rooms take shape and we are really pleased with the size of the window openings, particularly as we spent a long time last winter working through that element of the design. The joiners can't progress further until the steel arrives, this is delayed but due next Wednesday. In the meantime the scaffolders have been taking delivery of their kit and today have erected scaffolding on the west and south elevations. This photo is taken through the caravan window.

By and large we've had good weather since the start of the build, it is very mild at present which makes life comfortable for early mornings in the caravan.....however the past 2 days weather have included a large amount of rain and the area at the back of the house is somewhat muddy. Thankfully the caravans are on a concreted area.

Exciting Progress On Site

One of the landmark days on site - the joiners arrived at 7.50am, the first lorry and trailer load of timber frame a few minutes later. The first photo was taken around 9am as the timber was being moved to the house; the joiners spent much of the morning undertaking check measurements etc (apparently it was all within 5mm so that was good!) and moving the timber to the right place.

We had some wild Autumn weather at the weekend so it was a chilly post-frontal breeze as well as getting muddier around the site.

Timber Frame Disappointment

Today the forklift was dropped off in order to be ready for Monday when the timber frame is due for delivery. Three year old son just said 'wow' and is very excited that more machinery is on site. Unfortunately a couple of phone calls and a visit from the builder brings news that certain elements of the kit are not ready - namely the steel portal frame and the first floor TGI joists. This means that work can start on erecting the timber frame next week but the extent will be limited because the steel portal is to be integrated within some of the prefabricated wall panels on site. This is disappointing for us but is outwith our control or influence so not worth stewing about. For the builder it is perhaps more frustrating, particularly as there has already been a break of three weeks of fairly good weather since significant work on site and as he has lined up scaffolding and crew to go full steam ahead on the frame.