the first Certified Passivhaus in England, by Seymour-Smith Architectsthe AI PassivHaus

3rd June 2009

The poor guys on site have had quite a headache putting together this 3-D jigsaw puzzle, but have done a great job.

The waterproofing contractors, Specialist Jointing Services, have begun laying out the waterproofing membrane.  This product, Fosroc Proofex Engage, is unique in that it will form a permanent mechanical bond with the concrete that is poured onto it, thanks to the complex mesh on its upper surface.  This means that if any settlement takes place, the waterproofing will remain permanently bonded to the concrete.

By the end of day one, about a third of the membrane has been installed.  The pockets that have been omitted are for the fixing of precast concrete columns in a few weeks.  Insulation and waterproofing will be finished around them once they're in place.

5th June 2009

Day three of the waterproofing is a frantic race to get it finished before the rain kicks in.  The guys from SJS work incredibly hard, and thankfully get the job finished just before the tiorrential rain starts.

6th June 2009

And it's reassuring to see the next day that the waterproofing is doing a good job of keeping the water in...

9th June 2009

Robin's back, for one day only, to help Frank and Darren lift the reinforcement cages into place.  And Luke's girlfriend should take note that as well as being great at waterproofing, he's also pretty handy with a hoover... 

Pete enjoys the view, and makes inventive use of our Polypipe Polystorm soakaway cells - which will infact be a very important element in our surface water drainage in due course.

Gerry and Eugene crack on with making the ply boxing for the slots in which the precast walls will sit.

10th June 2009

Mike and Robert of Storm Geomatics do a final check that all of the edge formwork is accurately in place.

And it's all hands on deck to get the steel reinforcement and formwork finished before the slab is poured on the 12th...

11th June 2009

Frank & Co. put the finishing touches to the vast sea of reinforcement.  (The boxes they're standing in are column positions, to be infilled once the columns are in place.)

Dave of Faro demonstrates his fantastic Photon Scanner to the Grand Designs crew.  After only 3 seven minute scans, it builds up a complete 3d model of the site to enable us to overlay our drawings to double-check that all of the formwork is correct.  This is particularly vital for the ply box-slots around the edges that the precast wall panels will sit in - if we get this wrong, the panels simply won't fit - and they can't be adjusted like a bit of wood...  See the scan here:  

12th June 2009

A fantastically exciting day, as this enormous concrete pump turns up, and the slab is finally ready to be poured.

The first load of Aggregate Industries' super green Emerald Mix concrete is poured into the pump...

and Ed and Joe capture the exciting moment on camera.

Just over an hour later, the first bit has been finished smooth and sprayed with white Fosroc Concure WB, a very sensible alternative to polythene sheets, to stop the concrete from drying out too quickly as it cures, and to prevent cracking.

By lunch time, amazing progress has been made, and two thirds of the slab has been poured.

And by 4pm, it's all finished!  We felt we had to leave our mark on what will be the floor of the garage...

15th June 2009

Another amazingly exciting day (after six long months of groundworks), as the 100 tonne crane unfurls, and a sucession of lorries arrive carrying precast bits of our house.

The first precast concrete panel is lifted through the air - the easy bit...

... and then lowered into place under the barn - the not-quite-so-easy-bit, as Aka and his team from Premier Precast Developments apply their expertise to this tricky installation...

The panel has to be carefully tilted...

... skated into position in its slot, then lifted back up again...

... and when that's secure on acro props (to be winched, apparently effortlessly into the vertical later), on with the next panel...

Now that most of the formwork has been struck (following cube tests to check the strength of the concrete), it's wonderful to see the blue of the insulation on which the house sits, topped by the black and grey waterproofing membrane which has bonded to the concrete slab.

It really takes a bit of getting used-to, this 100-tonne crane, which is probably visible from three surrounding counties.  Just as long as they don't knock our barn down...

Along comes the next panel...  the rough stripes down the vertical edges (which will be on the outside) are where a concrete retarder was placed in the formwork, to expose the aggregate and give a rough surface to adhere the waterproof strips to.

16th June 2009

Day two starts with more enormous bits of precast concrete effortlessly sailing through the air.

Offcuts of the extremely strong Styrofoam insulation are being used as bearers for the beams and columns.  Although the whole slab is of course already sitting on this stuff, it's still very satisfying to see two small strips of it supporting a 2.5 tonne column.

All of the walls under the barn are now up, and the first column is lifted into place.  Despite the barn being in the way, these guys make the process look easy - and it really is amazing to see so much happening in such a short time.

Richard and Malc from the farm kindly pitch up to help with their "Redrock"...

which lifts into place a beam which the crane couldn't manage, under the barn gable wall.

By the end of day two, we have walls, columns and beams complete under the barn - excellent!

17th June 2009

Day three sees the concrete roof / floor planks being lifted into place, and by lunch time, it's finished...

... ready for the guys from SJS to crack on with preparing the joints for grouting.

18th June 2009

Another delivery of insulation arrives from Dow.  This stuff is called Perimate, and is for the outer face of the underground walls (in addition to the Floormate insulation that we used under the slab).

These shiplap-edged boards are specifically designed for underground walls, with vertical grooves in the outer face to prevent the build-up of any water pressure, and a geotextile membrane on the outside to prevent soil from clogging up the grooves.

Simon mixes up a batch of Fosroc's special high strength non-shrink grout...

... which will be used in all of the joints around the precast panels.

19th June 2009

The Grand Designs team are back - Mike and Tony seen here in the middle of the rape field waiting to get an arty shot of the arrival of the precast lorry.

... which brings more wall panels.  These ones in the area away from the barn slot into place extremely easily.

It's incredibly satisfying to watch, as yet another panel, beautifully constructed in a factory to very precise dimensions, fits perfectly into place.

The space is really starting to take shape.

And while all the precast structure has been fitting together on the other side of the site, the concrete planks that form the roof of the house and the floor of the barn / office are being screeded.  The team from CSC Screeding have brought a screed pump with them since access up to this level is restricted.  Steel mesh within the screed helps to tie the whole structure together.

24th June 2009

Innovative use is made of offcuts of the Dow insulation as shuttering for the blocks of concrete infill between barn and new concrete structure below.  This is so we can eventually take the steel frame away.

25th June 2009

Peter has done a fantastic job of manoeuvring the ply formwork into place in the very tight space around the steel.

And the guys from B A Hull, who are back for the week, fill the pockets created between the barn walls and the new structure below with concrete.

29th June 2009

Once the concrete infill under the barn has gone off, some adjustments are made to the steel frame around the barn, to enable the remainder of the precast structure below to be installed.

30th June 2009

With the barn secure, Aka and his crew from Premier Precast are back to finish the installation of the precast concrete structure.

Columns are installed along the central spine...

... with beams on top.  Complex connections are welded by local blacksmith Andrew Sked.

A slightly nerve-wracking moment as one of the panels that is doweled into the slab is lifted into place - will it fit?...

Thankfully (particularly as this is being caught on camera!), it does, like a glove.

The two central beams that have the longest spans have been designed to act compositely with the in-situ topping, so they must be propped like this until 28 days after the screed has been applied on top of the hollowcore floor planks.