ICF Started

The first blocks of ICF are now going onto the basement!  These blocks are forming the front-outside walls and main load-bearing internal walls of the basement.  With these up, we'll be able to walk inside our house for the first time.

The blocks arrive flat-packed from the factory and open up with the plastic internal ties locking them into shape. These are then stacked like lego and steel bars places along them for reinforcing the concrete.  For door and window openings the blocks are simply sawed into the lengths.  No morter or glue is required to hold them together, the blocks fit via a set of plugs on top and sockets on the bottom in a snug fit.

The gap between the polystyrene needs to be shut at the door and window openings, lest the concrete pour out!  Another piece of polystyrene slots between the 2 layers facing into the gap.  Some ICF systems just use wood either, and this has the same effect, the only difference is that the polystyrene sleeves have a better insulation, and it's at the door and window joins that you get a lot of issues with cold-bridging and drafts.  Drafts can be sealed with an expandable foam insulation, but cold-bridging is harder.. its where a conductive material (such as metal) runs from the inside where its warm to the outside where its cold.  This creates a conductive bridge between the 2 environments that bypasses the insulation layers, and leaks heat at a high rate.  It's tricky as where components join it's very easy to create a bridge unknowingly.. an example might be if screws from the inside were to connect to brackets that hold in the windows, and the bracket were to be on the outside.  Its the detail like this that can turn a warm home into a cold one.  In designing the house, there are lots of places these can creep in, and then all it takes is a tradesman to take a short cut and you leak heat (and money!)

So this week should see the build and pour of the basement sections.  I managed to procure a number of ducts from the HRV supplier to place into the walls before we pour the concrete, we'll also add a couple of other 6" or similar ducts to allow electrical cabling and the central vacuum to route through.  This will save drilling through the concrete later (if we've thought of everything).

So far we only have some of the walls complete, waiting on confirmation of the window sizes to properly construct the walls.

The weather right now is fantastic, long may it continue!!  In other news, the bank has re-approved our mortgage and once we re-sign updated documents we should be able to start accessing the money - a massive weight lifted off my shoulders on reading that.

You want money?? - Do you think we're a bank or something??

Cash flow is probably the more stressful part of the build in my opinion, all the other choices are positive in terms of how you want the house to look, or last over time, cost, etc but in general are positive, exciting things to think about.  Cash flow however is wondering who, when and how much you have to pay vs what you have in the bank.  No one like waiting to get paid and I resolved at the start to do my level best to ensure people get paid on time and stay happy.

As stated before the mortgage is paid in arrears, so not until we had the 1st stage complete could we start drawing down the mortgage.  Of course the catch-22 is that you don't want to sign any contracts until the mortgage is 100% available.  So in Nov we finalized and signed the loan agreements, with a 90 day period to draw down the 1st payment.  In that time we had to pick the builder, finailze the price negotiations, find a digger, wait for weather, etc.. but it was more like 6 mths before we were ready to draw down.  In that time we contacted the bank a number of times to ensure that the offer was still good, and if not is there anything we need to do.  All was well.

Until we needed the money that is.  Now the loan offer needs to be redone from scratch.  For anyone who has got a mortgage before there is a lot of documentation that needs to be assembled, all of which cross-confirms your potential to pay.  With the builder having bought the ICF blocks (on our site) he's left at the moment short until we pay the next stage.... and that certainly isn't fair on him.  What should have been a couple of days may turn into a couple of weeks.  And then of course there is the potential for the bank to refuse the application!! But I'm trying not to think of that.  So - all day is a scramble to get documentation together, rooting in various drawers etc.  Funny thing is both Lorraine and I bank day-day with the same bank and they have a more complete picture of our transactions than we do!!  Maybe they are looking to prove that we know what they already know so that they know that we know we can pay the mortgage.  Damn clever.

On the house front, we are delaying a day on starting the ICF walls because I don't know what size door to use internally!  All was fine until I visited a friends house and after a few minutes in there (and acting suspiciously around the door) I realised the door is subtly bigger than standard. It's not a massive thing, but I liked the effect.  It'll also be handy getting things in and out, such as myself when drunk!!  So, while I wait for a poor chap to measure up his doors at home we wait before starting as we need to cut the door openings into the walls as we build up the ICF.  At this stage though more delays are better until we have money to pay for the next bit.

Stress!

Floor poured, 1st Walls up!

After being away for 10 days, the site looks very different again.  Before, we had a layout on the ground and had to imagine how it would look as we went.  Now that floor is concrete, and with the rear walls of the basement up it's gone 3D.  The rear walls are huge to stand beside - over 3.5 metres tall.  A typical room with reasonably high ceilings is about 2.7 metres tall, so we're a metre again up.  For a totally useless piece of information, the weight of just this section is about 340 tonnes!  Also completely useless is the fact that if you had a big enough crane, you could actually lift the entire structure up - the radon barrier completely separates it from the ground underneath.

There is an access panel for brining in the live ESB - it comes in at the base, in the floor, up through the wall into the meter box, then back through the wall up to the top of the wall.  This can then route into the suspended ceiling that will hang from the roof and route in the far corner in the picture (left most corner) - it comes in from picture right.

The wall itself is watertight (due to the amount of cement in the concrete) but the back of it nearest the wall needs to be tanked - that is made watertight (more so).  This involves placing a layer of waterproof membrane all along the wall and bonding it to the Radon barrier that is also waterproof. You can see the tight space that lies in here

The radon barrier is cleaned off and wrapped up tight to the wall and the membrane overlaps it.  Also in here we need to place a drain, as even when it's dry as today the back wall is weeping water.  A layer of drainage stone goes in, another of the yellow land-drainage pipes goes on top, and we fill in with more stone to above where the wall is damp, about 1.2 metres.  Where this picture is now will eventually be right under the main house itself.

We marked out the internal ICF walls as well, these will start to be assembled on Wednesday, and will form the rest of the outer walls, as well as some load bearing internal ones.  By Saturday, we're likely to be ready to pour these with concrete, and we'll have the first section of the house structure complete.

Before we pour, there are a number of services that need to transit through these walls, and we'll place pipes where they cross through before pouring.  This prevents us later having to drill though the mass concrete. All in all, now most of the tricky stage is complete, and with hopefully a few weeks of fine weather that you expect as all the poor students sit down to write exams, we can get cracking and make a good push on the build.  Finally - our nutritious grass and diesel fumes are having a positive effect on the local wildlife with a new lawnmower gambling about, no fear of our grass getting out of hand.

Radon-on

The weekend sees the floor coming along - the Radon barrier is down, steel cages are all in and the first set of pipes have been placed by the plumber.  With the radon barrier providing a sharp contrast in colour, the house outline is even clearer to see

On the left-hand side is where the basement bathroom will be, and the 2 long pipes in the center allow for cables to be run from the back where the electrical switchboard will be to the front for whatever purpose - outside sockets, gate intercom etc.  Great idea from the engineer and will save us a lot of bother in future when we wish to add or change any such cabling.  Of course, all I can think of is that it'll be the perfect way for Rats to get in as well, perhaps we should have made the diameter big enough to flush them through with a cat every so often.

With Monday being a bank holiday, realistically it will be Wednesday when the floor is poured.  With that finished, we'll have finally reached a stage where we can access our mortgage, and fingers crossed that it will still be there.  We have all the application signed and returned, but until you draw the funds it's still a little up in the air, and since we signed in January (with 30 days to draw down) its a little bit of worry in case anything has changed.  Our broker & bank have it on hold, but who knows.  It's a funny way of providing a build-mortgage, but you don't get any money upfront to start the project.  As you build (and add value to the site) then the bank pays you in arrears for that value.  This leaves you having to manage a tight cash flow, and all the unforeseeable extras serve to tighten the screw.

So by Wednesday I hope to have another milestone reached.  Again the clock here is to get weather-tight by the end of September (I won't say Summer) to allow us to work inside over Winter.

Shuttering the floor

With the pads in and ready, the surface to the pads has been flattened and shaped for the raft to be poured.  Yesterday, the shuttering outlining the area of the raft was constructed, today steel cages are being positioned into this as well as pipes for the basement bathroom/electrical conduit etc.  The radon barrier also has to go in, but we require 1-2 fine days for laying this.  Once all this is set up we can pour the first substantial concrete mass, and the first floor of our house is there.  We'll be able to see the outline of the area and see the real size of the living areas, especially as the walls start to be built onto it.

The notch in the middle of the photo outlines where the front door will be.  Aiming for this to be filled with concrete early next week, all going well.

Choosing our Architect

(Spoiler : To see what we're building a summary of the drawings can be seen here)

One of the first things we had to do, and as a result its intimidating, is finding an architect.  As I know nothing about building I was concerned about being able to pick the 'right' architect, someone who could deliver a house that was different enough yet within a relatively tight budget.  We hoped for something less than traditional and would stand out a bit.

The first architect we talked to was a recommendation from a friend, who incidentally has a fantastic house.  We got an initial draft done of what he was thinking having looked at the site, and we were excited.  But we of course wanted a couple of opinions so solicited a few more.

The second we talked to also designed a house we knew of, but on seeing the location of the site didn't think that we'd get a house of the scale we wanted through planning, and strongly implied that he didn't want to make any waves at the planning office.  In my opinion, that's exactly what we're paying for (note: we're paying, not the planners!) an architect who will make the most of the regulations and policies set by the planners - push the envelope if you will.  We wanted a fighter.

The final architect we wanted to talk to first sent us off to look at a couple of houses in the area he'd designed before he'd talk to us.  If we were still interested then we were to ring him.. Homework.  We duly went and acted suspiciously outside a number of residences, concocting unbelievable cover stories in the event we were rumbled, when in fact the truth would have probably got us an invite inside and a chocolate biscuit if lucky.  On driving around remote country lanes we thought it may be difficult to see which house may be his.  However, every time the house immediately sprang out at us as remarkable in its situation.  They had a different look and feel and really looked like a custom house, not one pulled off a book of house plans.

So we went further, happy with our homework done we went for an interview... and it was both ways.  This guy didn't want to know if we wanted a straight-forward house, he wants to design a house, not throw it up.  Having blagged our way through that and accepted ;P we left with more homework - a wish list of what we wanted.  Open question and deliberately so.  At the end of this meeting, we knew we'd found the guy.  He let his portfolio speak for itself and was only interested in delivering something out of the mundane.  Looking back at no point have we regretted our choice as we're very happy with the outcome, as well as his management of the planning process.

The planning process isn't a one-way street.  There can (and should be) initial meetings with planners to set the tone of what is being suggested and how that fits in with the policies for the area.  The earlier that happens, the quicker the boundaries can be set and we can concentrate on designing with what will be allowed, rather than wishful thinking.  The initial meeting went very well, with positive noises from the planner.  Throughout the design process any significant additions or changes to the house was ran past them, usually as part of other interaction, and if we overstepped we removed and looked at it again.  This is also the benefit of having a local architect on the job (either as the principal or in an advisory role) as they will be very familiar with the local restrictions and personalities involved.

With anxiety we submitted our application for planning, our house is in an 'Area of Special Interest' and with the commanding view it also suffers from the opposite - it can be seen from everywhere.  While we had been in regular contact with the planners, the matter of the triangular windows at the front were a grey area up for debate.  We had compromised in removing the 1 1/2 story high front window, but it was far from certain.

Thankfully after the initial period had passed we were granted permission in one pass, with conditions but nothing that was too onerous.  The first hurdle was vaulted with no faults conceded! A night of (mild) celebration followed, and after that the sleeves were firmly rolled up to get to grips with what the task to hand was.  From there, it took another 6 months to arrange finance, agree a contractor for the structure, and line up the major trades to follow!

Wonderbar.. the padded foundation for extra 'lift'

Foundation pads have now been shuttered and poured.  These are 'lean mix' concrete poured into wooden shutters (to define the size and shape of the concrete) that were placed into the holes dug at the end of the initial groundworks stage.  These reach down to the hard rock substrate and provide a solid platform for the front of the raft to sit on, keeping it from sagging.  No supermodel pictures to advertise it unfortunately!

For those that really want to know, you can learn a lot about concrete here.  In short - a major determiner of concrete strength is the cement-to-water ratio - less water = stronger and a lean mix is a mix with a low water content. (The downside is that as its less fluid it's not as easy to work with).

So about 10m3 of the foundations are poured.  48hrs to cure enough, and on top of that a beam will run connecting all 4 pads and rising up to the raft.  Then we have a radon barrier, and the raft itself!  Then (finally) we can start building some walls and get a real feeling that the house is growing out of the ground!

22/4/2010 - The top of the pads having been poured to cap them off.  Starter bars were retrospectively added to the pour above (change of mind by the engineer) and brought up

With Starter bars to hold the 2 separate pours together..

And capped off with a pour - the raft will sit on top of these.







And finally with the shutters removed and the stone leveled off (23/04/2010)

Scorchio, bbrrrrrrr

The heating system has been a constant headache since day one of the project.  As a technical piece it's also held the most fascination for me after the structure itself, with a background in Physics all the theory and design appeals to my illusion that I still remember what all the mumbo-jumbo was about.  However despite being decided, its not entirely risk free the way we've gone.


The system we're installing is attempting to be cost neutral over the medium term, return over maybe 20 years at current prices, and if Carbon Tax and oil goes as expected then return shorter than that.  It should also reduce the mess and hassle of oil, namely a dripping tank and calling for for refills.


We're fitting a flat-panel solar collector and an air-source heat pump (A2W).  The solar collector is as you'd imagine - a panel set on the roof that heats a liquid (not water) that circulates through the panels into a central tank.  The A2W pump looks like an air-conditioner, sucking in air one side and drawing out latent energy, blowing cooler air out the other.  It works just like Geo-thermal but without the ground pipes which are unsuitable for our site (horizontal) or too expensive (vertical).  This too feeds into a central tank - 600L in size.


This central tank or buffer store is kept at a temperature of about 40-55 degrees by a combination of these 2 systems, with an immersion coil as a booster in the event of these failing.  From this tank, domestic hot water is acquired by drawing cold water in one end, through a large coil and emerging hot at the other end.  The water in the tank isn't directly used, the energy is transferred.  Similarly, the underfloor heating draws water from this tank and is pulled on demand into each heating zone.  A thermostat in each zone monitors the temperature and when it falls below the requires a little motor in the UFH manifold opens and lets more hot water in.


Finally, we're adding MHRV.  This is mechanical Heat-recovery Ventilation and makes a huge difference to the efficiency of the house.  Air is drawn from rooms that tend to be damper (bathrooms/kitchen), up through an air pump and out.  Air is drawn in by the same pump and a honeycomb in the middle of the pump allows the the two air flows to be close enough to transfer heat without the gases mixing.  So you get warm fresh air pumped into rooms such as bedrooms and living rooms.  The motor only uses the energy of a light bulb.


The risk we're taking?  Well - the size of our build suggests a bigger heat pump than we're installing... but I'm heard a lot of anecdotal evidence to suggest the performance of an ICF house is better than an 'average' house.  So I'm under-spec'ing the heat pump now and will monitor it's performance over then next year or two, and if we need to bolt on more than we can look at the options then.  It's better than a bigger spend now at a cost of higher heating rates, but even with that it'll still be less than using Oil for a year.  


So - now thats decided, I can stop talking about my pet topic and concentrate on the more mundane items!

Slowly, slowly, catchee monkey

No visible progress on site this weekend, although the engineer has signed off on the holes dug for the pads.  They are in the right place, which is nice, and on Friday we had another look around as well as deciding how to route in the ESB mains, water, and other conduits required to be added into the base and walls.  Its funny just how many little things there are to think about, the minutia of it can sometimes leave me slightly stressed that we're missing something that will require a lot of work to rectify.

This week I was supposed to be in the US for work, but Vulcan has deemed otherwise and so I'm left here instead.  While disappointing in itself it means I can sort out a few things that would have been otherwise difficult.  We've closed on the heating system, a major expense factor on par with the roof, and will be able to tie up a little legal juggling with the structure contractor easier with Lorraine and I here to sign contracts.  So while nothing looks different we can start to build on the details required to ensure these items fit correctly, and avoid hacking through mass concrete at a later date.  Our plumber is on standby to drop up and see what pipes he needs to lay before the floor is poured, and we'll place some ducts for electric cables to allow access to the outside front area.

Expecting the concrete pour to happen this week into the pads, Tuesday is likely.  48-hrs to cure and back fill and we can start the raft proper at that stage, and things should really start moving then.

Preparing foundations

With the bulk excavation finished the site looks very tidy.  We now have a large area at the front where the basement will sit all nicely graded off with stone.  Also, we have 4 deep holes at the front for the pads for the front of the raft to sit.  I believe the instruction was to dig until they found rock and as you look across the site that is found from about 2m down to nearly 3 on the side nearest the entrance.  When I got there though, it was a bit of a shock to see what was actually the case.  Naturally, everything you're being told is passed off as 'just a little pad of concrete" or "just have to take that back a bit" or "just a little filling of stone".  When you see what the reality is then you need to adjust a bit and realize that frames of reference are not aligned.  Little is dependent of whether your the one paying in my opinion, and a practical exercise in their opinion.  A day of filling stone might not be a major exercise to do, but expensive to pay for.  Tip number 1 - ask how much its likely to cost!

The cross section is interesting.  The hole is the guts of 3 meters deep for a start, just to give you and idea of scale.  The top section is stone filling we've added.  The black strata looks almost like an embryonic coal seam (the area is riddled with tunnels from the old Rossmore Collieries, the dancing boards mentioned are 2 fields to the south of our site) so i can imagine that if that was further compressed over time it would become coal.  Finally at the very bottom is solid rock rather than the light shale  that makes up the bulk of the substrate.

In terms of (over)spend, the excavation was 50% more than anticipated.  This is mostly due to hitting the springs under the basement, the resulting drain and tidy up of the saturated and useless clay.  The start of what I guess will be many overruns.  We also have an as yet unknown cost of the stone filling, is was drawn on demand, so I expect another financial ripple to roll across my spreadsheet.

But - its important to be house (or site) proud and maintain it in the way you intend.  With that we have the latest in ride-on mower technology keeping our lawn trim, utterly autonomous and self-maintaining.

Now steel is coming onsite that will be used in the pads and raft foundation cages, hopefully this will start today/tomorrow and we can see the first baby steps in construction.  Also this brings us closer to the time we can access the first draw-down on our mortgage - up till now we've been paying all the costs out of our savings and will need to access the bank's money soon!