Airtight tape and shutter blowouts

This weekend saw the roof areas being poured with concrete (over the insulation and DPC).  Unfortunately though there was a problem - the shuttering parapet didn't hold and blew out.  They started on the small area first and when that went the larger area was left.  Its messy, and puts more delay on getting it done.  The issue wasn't the wood shutters, or the ICF plastic tie in points, but the screws that were used to hold it in - they snapped.

Hopefully we'll be back on course to get another try with reinforced shutters tomorrow.

On the inside, the detail around the window and door openings continues - I poured concrete behind all the window sills on the top floor (so no more lugging buckets of concrete up there!) and have the basement and 1/2 the middle floor left to do.  I also started taping windows where I've poured the concrete.  I'm using a SIGA tape - its expensive stuff but its well designed for the job.

The tape sticks around the edge of the window frame and across the gap onto the wall reveal of the ICF.  This gap is filled with foam by the window installers, but that foam isn't airtight, so its a source of drafts and in winter that means cold air pouring in.  So the edge of every eindow and door needs to be taped up.  Its fiddly work with a small knife, and the tape is super-sticky, so your fingers get all glue'd up.  Also, sinve the gap between the window and wall is never uniform you end up having to patch parts of it - its not as easy as the guy in the video makes it look!

Here is the window tape - Corvum 12/48.  The window is sealed, but I also need to add tape to seal the inside EPS to the reveal - once I cut the metal window pins back to the minimum size.

As well as the windows, anywhere a pipe exits the building is a source for unwanted air to come in.  The key is to try and only have the MHRV as the source for air in the house - that way all the air coming in is pre-warmed.  Rissan tape is used on the pipes - and if the window tape is super sticky this stuff is unbelievable.  I'm like a football commentator running out of superlatives.

Here's some of the Rissan on a 4" waste pipe

Flat roof tanking

Flat roof tanking is underway - ideally it would have been finished but - as usual - there are delays in getting work done with this builder.

The flat roofs are particularly difficult to ensure they are watertight.  We also need to reduce any heat loss.  The engineer has specified a detail as follows:

Its basically a layer of insulation, covered by a DPC layer, on top of which is a layer of concrete that overhangs the wall on which the roof sits.  This concrete is leveled with a gentle fall to the gutter.  Flashing on the wall should prevent water getting under the DPC layer by dripping down.

So - as this gets assembled we have the following for the insulation clad roof with the overhang shuttered

Then with the DPC layer on top

Clearly lots left to be done.

Also the first fit plumbing has gone in, with the first electrical fix to follow.  There is an insane amount of cabling to go in, with a decent spec on the usual's, and a lot of Cat 6 cables. there will be a lot of runs.  The vaulted living room ceiling and the stairs poses interesting areas to light in a suitable way, that also allows us to make a feature of it.

We've also booked in plastering in and out to start in 6 weeks - worse case we'll get everywhere but the front door plastered.

Stairs complete

Finally the stairs is complete - the sage of this has been a bit of torture, and has held up a lot of the work that needs to be done over the next week - that will then allow some parallel work to take place.  The concrete will be finished off with a stone cladding on the topside and plastered underneath.  

With this in place the windows can be installed and the roofs tanked giving us a weatherproof house (bar the front door and 1 window) and plumbing 1st fit can begin next week.  There are some changes in the design that will effect the plumbing, a bit of concrete slab chiseling will be required as well as getting out to the outside for waste pipes. These will have to be carefully sealed afterwards to prevent future air and water ingress.

So plan for the next week:

Thursday - Window install
Wed -> End June - Roofs tanked
Sat - mark out the plumbing areas and get cutting the concrete, seal off the front door area with timber to prevent access.
Next week start 1st fit plumbing.

Filling in the Sills

The window sill work got started on the weekend.  The timing was dictated by the fact the bay window needs to be fixed into something solid at the bottom - this is a job that needs to be done but not until 1st fix carpentry when the window boards would be going in.

The thing here is to ensure that we dont' create a massive cold bridge by the concrete filling conducting heat into the stone window sills.  To do that, the DPC membrane is pulled up tight on the sill and against that a 1" thick layer of ICF insulation is placed along the DPC.  Then concrete can be poured into the gap between that insulation and the internal ICF wall.  I used can-foam to try and fill any gaps at the bottom or where multiple sheets of insulation were used.

2nd Lift

The second lift of the main staircase is being formed.  After a lot of wrangling over the measurements, number of steps, start position etc the formwork is going in and hopefully ready for pouring next week - the idea will be to get this framed up and then get the roofs shuttered up for pouring and hit them at the same time.  This will give us access to all floors and a weather-tight house for fitting.

From my jobs, yesterday was mortaring up the joints in some of the window sills.  A good evenings work.  The HRV is fully ducted and nothing more to do on that until we're slabbed and skimmed.  

Solar Panels Installed, 2nd Flight of stairs finished.

Yesterday saw the Solar panels installed on the roof.  We had a delay in getting them placed due to weather, it has been windy for the last week making it difficult to control a large square panel as its hoisted up the scaffold.  However it's in now and provided another good excuse to clamber around on the roof.

These should give us all the hot water we need in the Summer and late/early spring/autumn reducing the cost and running on getting this from the electrically fueled A2W heat pump.  There may be a little gain during days we need heating from this array, but its negligible.  As part of the package, the company installing this is also supplying measurement gear to monitor feed and return temp from the collector, so we'll be able to see what positive effect they have.  Sadly we can't get these facing south for maximum efficiency - changes in our layout prevented that.  These ones face East with the setting sun in the picture behind them.  The main reason for picking East is as much in shortening the pipe run as anything else, but we are also slight occluded by the ridge behind us in the late evening - whereas we'll get full  effect from the morning sunrise.

Also installed is the J-Rail for the Facia/Soffit that will finish off the roof.  This clip needs to be added before plastering the outside, while thats a bit away getting it done now took advantage of the residue scaffolding from the roofers, as well as one less task to schedule.

This corner of the eves has the black rail attached.

The second flight of stairs, and the first one of any size has also been poured and set, and the wooden shuttering is being taken away.  This now has to cure for 9 days from pouring before the third and last lift is formed.  We think it's going to look great, already the shape of it is fantastic and the rest of the wood in the picture below will be taken down - the central section will be a void running the entire height of the house.

The HRV pipes are installed throughout, these will take and return air from the building recycling the heat as it exits.  Coupled with airtightness around windows and doors this should decrease the amount of heat required to maintain the building temperature when cold.  These are large 200mm ducts with a silver bubble wrap lagging - here they are in the riser with the black-lagged solar feed/return pipes beside them

The Central vacuum pipes should be going in today, as well as delivery of the bitumen layer for waterproofing the flat roof sections.  With our front door detail agreed as well, we can finish off the main structure and have it weather tight  enough to start the electrical fit and start the outside stone and plaster.

Chimney finished off

The Windows are continuing to be installed - 90% are in now with some of the trickier windows left.  Access is an issue with the stairwell unfinished, but this should resume on Monday.

The chimney is now finally finished - epic tale to get a simple thing done.  The Capstone was the hardest issue, that is now installed, however the detail on the chimney wasn't fully correct so we had to go back up and finish the job ourselves - the added mortar stops rain from pouring into it.

It's also a good excuse to get right to the top of the house.  We're up here as next to this is where our solar panels will go, so scaffolding had to be rigged to access it.  These will hopefully be installed early next week, another job finished.  With scaffolding up we can also take the opportunity to get the J-Rail up for the Facia/Soffit to connect into.

Window installation

The windows are onsite and are being installed.  An articulated flatbed rolled up last Wednesday and struggled to unload the windows - about 47 in all.  I was surprised at the way they came, largely the frames and glazing units separate and fitted onsite, but I can see the advantage as it's easier to get the frames up square and pinned when they weight nothing, then add the heavy glazing units.  So far no major issues with the windows - they seem to fit!  Only problem is around the half-finished stairs as there are no level areas to get scaffolding in place - we may have to fit these on the second Window fitting.  Below you can see some of the windows in the basement.

It throws up some work for me to do again - some of the easier items are wrapping the sills and windows in plastic to prevent damage when we plaster/stone - and some heavier gauge stuff near where concrete will be pumped.  Easier to do this now than try to clean them later - mess is inevitable, and I  have no confidence that our builder (of the stairs) will be neat and tidy enough.

Also I need to insulate the back of the sills.  The sill fitters were a little messy with concrete beds for the sills - the DPC layer won't pull up tight against the back of them, and I can't chisel it out due to risking cutting the DPC layer.  So I'm thinking of using a sprayfoam to cover the concrete, polystyrene on the back of the sills above that, and then concrete into the remaining space to fix the window boards to it.  Can't think of another way to wrap the insulation better.  Also I have to plug the sill ends with offcuts of ICF.

With Windows in we're almost weather-tight, there is still a good bit of flat roof to get tanked.  But if the house is secure then we can start the 1st Fix of anything that won't get too effected by weather - HRV, central Vac ducting and plumbing.  Electrical and carpentry I'll leave until the house is sealed, that's also the best order to get things done.  

So this week I have to get the following moving, these are the in between tasks that going direct labour gives me:

• Secure scaffolding for Solar Panel fitting
• Get the Stairs moving again and after that the tanking of the flat roofs
• Plastic up windows and sills, plug sill ends.
• Airtight tape the inside of windows and doors.
• Shut off any openings - front door isn't in place yet.
• Get the HRV guy in - should be next week
• Get the Vac guy confirmed the week after
• Plan out room layouts for electrical and plumbing fix - I have about 4 weeks to get this.

No rest!

Heating update

The heating engineer arrived onsite for the first time to do a quick survey. A minor change to the kitchen has had a(nother) slight unintended consequence - we moved the back wall out a foot or so, and this has reduced the area of the roof we had set aside for the solar panel array.  So we now have nowhere for an optimal south facing collector to be positioned.  We can still position East-West but it won't give us as high a return in energy as otherwise.  It's still worthwhile, if we switch from a flat-plate collector to an evacuated tube collector the mirror lens under each tube will focus the incoming rays to the centre of the tube from a wide range of angles.  Pity.

Apart from that, the cap-stone fro the chimney is now causing an issue - its very heavy and our builder has bailed out of the offer to manhandle it up to the top.  A crane willbe very expensive to hire - I'm wondering if we can go old school about it and construct a block and tackle frame against the rafters, with the A frame above the height of the chimney and haul it up.  If the Greeks could do it, then so can we.  Thank you Archimedes.  Of course it may well be rubbished by the experts.  Happens a lot.

Progress

With the thaw and a bit of messing on stairs measurements and window measurements, we're now tipping away again.  The stairs is being formed in situ, which looks quite complex due to the spiral.  Wooden formwork is up to shutter the concrete, with steel rebar into the walls and through the stair structure.  Since the stairs floats away from the walls at places, its quite an interesting feature overall.  Here is the basic formwork for the 1st flight beginning to take shape.

The wood forms the base of the steps, and the centre drum the centre of the spiral.  All the wood will be removed once the concrete sets leaving space in the middle.

Apart from the stairs, we have the window openings measured by the supplier and contract signed.  We need to bverify a couple of details tonight and they start to manufacture the windows.  In preparation for the fitting there was a bit of work to do over the weekend - where the doors are placed in I needed to cut out a step for the frame to sit in.  This allows a proper damp-proof-course layer to be placed in, and prevents water collecting where the door and house meet at the bottom (the water collects, but below the level of entry into the room).  It also reduces the step over the frame at a later time.

First I cut out the markings with an Angle Grinder - this was to promote sharp defined edges for the next stage of hammering out the concrete.

It's not muc concrete to be removed in terms of quantity, but it takes a long time to hammer out this stuff, even with high power tools.  I'll level off these cuts with a screed to bring it to the right height and level and then install DPC before the doors are installed.

We also attacked the interior tip that our house has become, with hours of sweeping we now have a very clear main floor and basement areas.  Roofers have yet to finish and upstairs will then be tackled.