360 Winnett » insulation

And Then There Was Drywall

jeremybell — Sun, 05 Apr 2009 05:04:52 +0000

It’s been 222 days since we began construction, and we finally have drywall. I’m actually shocked how quickly everything was installed—The insulation and vapour barrier was delivered on March 21st and subsequently installed on the 31st. Drywall was delivered on April 1st, and installation was completed this afternoon. They still have to mud, tape and sand everything, but for some reason I thought it would take a little more than 3 days to install the boards.

The installer’s efficiency has been quite remarkable and they seem to be leaving very little waste as well. I originally didn’t understand why they’d install 2 boards, skip a spot and then install another 2… but after noticing it in various places around the house, I realized they were leaving the odd sizes until they had leftover pieces that could be cut to fit. I’m also impressed their craftsmanship… These guys clearly understand how to measure and use a router.

For the most part we’ve used 1/2” drywall throughout, although we have 5/8” type X board along the south wall (which is close to the lot line) and Durock cement board around the tubs and shower.

All in all, I’m quite happy with how everything looks so far. I was certain that the rooms would all feel smaller once the drywall was installed, but thankfully that’s not the case.

I’ve posted a number of photos here.

Something Blue

jeremybell — Fri, 27 Feb 2009 02:23:45 +0000

When it comes to insulating a roof, there aren’t many options… and in the case of a flat roof, the options are even fewer. A traditionally pitched roof has a large ventilated space that sits between the insulation (typically cellulose or fiberglass) and the top of the roof. With a flat roof, there obviously isn’t room for the same ventilated space and you’re forced to take a slightly different approach. While it is possible to install a ventilated option, we opted to make the entire roof cavity airtight with R40 worth of BASF Walltite.

According to their website, Walltite is “is a polyurethane insulation/air barrier system intended for institutional, commercial, industrial and residential use. It provides a gap-free, airtight, monolithic envelope of low permeability that adheres tenaciously to virtually all surfaces, smooth or irregular.”

There are actually 2 kinds of polyurethane spray foam; Open-cell (or 1/2 pound), expands to about 150 times its original volume, however it is not considered a vapor barrier and only R3.6 per inch. This means you need a lot of it to achieve the R-Value you desire, plus you need to then install and tape 6 mil plastic as the vapor barrier. Closed-cell (or 2 pound) expands to about 40 times its original volume, is considered a vapor barrier and is about R5.5 per inch.

On the day of installation (which has to be above -10°C), a crew of sprayers arrived at the house, covered everything that wasn’t being sprayed and promptly filled every void with the bright blue foam. Apparently this stuff doesn’t come off once it’s applied and the last thing we wanted was blue stains on your newly-installed windows.

The garage ceiling was sprayed to R30, including the main HVAC stack and ductwork that runs along the inside wall. The floors of the exterior overhangs were both sprayed to R40, while the joist ends were sprayed to R30. We also sprayed all of the steel posts to ensure a thermal break was achieved.

In an ideal world, we would have sprayed everything… however, our pocketbook disagreed ever so slightly. In the end, we settled on a compromise of sorts and went for a mix of Walltite, Roxul and 2” of rigid exterior foam.

Of Insulation & HVAC

jeremybell — Wed, 26 Nov 2008 23:08:33 +0000

One of our goals with this project has been to construct the most energy efficient and eco-friendly building envelope possible. This has required that we pay close attention to the various insulation values and invest in the most efficient HVAC system we can afford. Regarding the insulation, it’s looking like we’ll have the following:

Basement Walls: R-22.4+ (ICF)
Headers: R-36.4 (2” exterior rigid + 4” sprayfoam)
Exterior Walls: R-32 (2” exterior rigid + interior Roxul)
Roof: R-40 (6” sprayfoam)
Overhangs & Garage Ceiling: R-62 (9.5” sprayfoam)

Under Garage: R-10 (2” rigid)
The R-value of the overhangs and garage ceiling seems like overkill to me, however our mechanical engineer insists that we completely fill the void to eliminate air movement and reduce the potential for mould buildup. It’s obviously hard to argue with that. We had originally planned on using a closed-cell sprayfoam everywhere, however that proved to be far too expensive. As a result, we’ve decided to use 2” rigid panels on the exterior, plus Roxul on the interior.

We also need to make some decisions in regards to the actual equipment. We had originally considered geothermal as a possible solution, however it was incredibly cost-prohibitive when we ran the numbers (cheap to run, expensive as hell to install). As a result, we decided to go with something a little more traditional and we’re currently leaning towards the Carrier family. Specifically, we’re considering the following:
Infinity Zone Control
Infinity 96 Gas Furnace
Infinity Series Heat Pump
Performance Heat Recovery Ventilator
Performance Series Humidifier

Infinity Air Purifier
I’m not 100% sure if we really need an air purifier, but it would be an obvious plus. I’m also unsure about the heat pump. As I’ve mentioned before, a heat pump works as both an air conditioner and a heater. However, it only operates as a heater in “cool” temperatures which means it’s unusable when the temperature drops below -3°C. Given the Canadian temperatures, I’m unsure if the heat pump really makes sense or if we’d be better off relying solely on the furnace for heating and a more efficient air conditioner for cooling?

Similarly, while I’m digging the Carrier products, our HVAC installer is recommending KeepRite instead. Everything I’ve read online suggests that they’re decent (and cheaper), but not as good as the Carrier offering. I’m not exactly looking for the best of the best, but I really like what the Infinity line have to offer. In particular, the control unit supports up to 8 zones in the house and can independently control every facet of the system (heating, cooling, humidity, fan speed, ventilation, etc.) Obviously this requires that each unit be part of the Infinity line, but it’ll mean the system is also working as efficiently as possible. They may be cheaper, but I can’t imagine the KeepRite products are really comparable in this regard?

Photo via Flickr user targophoto.com

ICF to the roof?

jeremybell — Wed, 16 Jul 2008 03:24:07 +0000

I’ve already discussed the benefits of using ICFs for our foundation, but we’re now considering using them to construct the entire building envelope. We had originally expected it to be cost probative, but after getting a few quotes it appears to be comparable to traditional stick framing with spray foam insulation, which makes it far more palatable than we anticipated.

As with the foundation, the main benefits are the same: Fire Resistance, Sound Resistance, Durability, Energy Efficiency, etc.

I’m not anticipating we’ll see the benefits of their fire resistance, but it’s comforting to know it won’t exactly burn down in a matter of minutes. I’m also not expecting the home will see many wind storms or earthquakes, but I know it’ll hold its own in the face of mother nature.

Sound dampening is another great byproduct, which really shouldn’t come as a surprise once you think about it. The foam and concrete acts as a sound barrier, which dampens sound vibrations and renders the interior eerily quiet. I can’t say this is something I’d necessarily seek out, but it’s also something I won’t complain about it.

I suppose the most valuable benefit of using ICFs are the inherent energy efficiencies that they provide. The foam alone accounts for an R-22, but if you take into account the thermal mass of the concrete, you end up somewhere around R-40+ (or so they say). Similarly, the continuous application of foam and concrete ensures there will be minimal air leakage, which furthers the structure’s energy efficiency.

From a construction standpoint, we’ll also see a number of additional benefits such labour savings and speed of deployment. But of course, we’ll also see a few drawbacks.

Our design calls for 2 cantilevered overhangs, however the concrete adds a considerable amount of additional weight which hasn’t been taken into account. As a result, we’ll have to reevaluate our structural needs and will probably substitute steel for of the engineered wood beams we’ve accounted for.

Another issue we’re facing is a slight reduction in usable space. If you look at the 1st floor drawings, you’ll see we’re already pretty tight between the kitchen, stairs and garage. It may not seem like much, but the ICFs will consume an additional 4 inches on both sides of the house and we’re a little concerned about loosing those 8 valuable inches. Altius has some ideas, but I think we’ll ultimately need to be a little creative to make it work.

We haven’t made any decisions yet, but we have a meeting this week with our contractor, architect and ICF installer to discuss the realities of this approach.

Under The Garage

jeremybell — Mon, 23 Jun 2008 13:07:10 +0000

I don’t believe this is particularly common, but we’re planning on building two extra rooms in our basement by excavating the space under our garage. In a typical garage, the floor is simply a concrete slab that sits on top of soil, however we’re going to approach things a bit differently.

Because our foundation will be built with ICFs, we’re planning on utilizing a “deck” system that will integrate a structural concrete slab directly into the foundation itself. This means we’ll be able to pour concrete for the foundation walls and the garage floor at the same time. When everything cures we’ll have a structurally sound garage floor capable of supporting the weight of a car, plus a completely insulated 10×20 space below it.

The decking system is pretty straightforward to install—Once the ICF blocks have been assembled, the foam deck panels are placed across the span that makes up the garage floor. These panels are then supported from below with temporary shoring and reinforced with rebar.

Obviously this approach is going to cost a little more, what with the additional concrete and rebar and foam panels and labour, but we’ll be gaining an additional 200 sqft of space that would have otherwise been inaccessible. If you take a look at our floor plans, you’ll see that we’ll have a very generous “study” and additional storage down there… which I’ll say is a decent use of that space, no?

For those itchin’ for the nitty gritty of how a system like this is installed, I also dug up a PDF aptly named Pouring A Structural Slab that explains it all.

Energy Consultation

jeremybell — Sat, 14 Jun 2008 23:07:10 +0000

As part of the design process, we’ve also begun working with an energy consultant who will help us define the HVAC system for the new house.

The first step in defining the system is determining what the heating and cooling requirements will be. To determine this, a data model is created that takes into account the house dimensions, density, amount (and type) of windows and doors, R-values for walls, roof and foundation, plus a variety of other inputs.

The output is then used to determine the HVAC sizing, layout and design. This includes what types of mechanical systems we will use, plus how the ductwork will be run. Our original intention was to use a high-efficiency furnace and A/C unit, but our consultant presented a few additional options for us to consider. We discussed at length the merits of a geothermal setup, but the costs are quite significant. The government does offer up to $7,000 in rebates, but it’ll still be hard to stomach the difference. If we don’t go geothermal, he suggested a high efficiency furnace and a heat pump instead of a traditional A/C unit.

A heat pump is basically an air conditioner in that it will extract the heat from your home in the summer, but will also pull heat from outside air in the winter. In many climates, this setup is enough to cool and warm the house year round, but in Canada we would still require an additional furnace. The beauty of this dual-fuel setup is that the two systems share the heating load, each system operating when it is most cost effective. The heat pump does most of the work, but the furnace takes over when the temperature drops below the heat pump’s ability to operate efficiently.

Regardless, our consultant will be providing a detailed cost/benefit analysis of the various options so we can make an informed decision. He’s also made some recommendations regarding the building envelope.

From an insulation standpoint, he’s recommending we take a “20/40/60” approach. This means we’d have a R-20 foundation, R-40 walls and R-60 roof. This is well above code and while I completely agree with the approach, cost will be the deciding factor. At the moment, we’ve only budgeted for 12/20/30, and I fear the price will outweigh the diminishing returns. We’ll still get it priced as I’m curious what the delta will be.

Photo by Flickr user jtuason

$10,000 in Rebates*

jeremybell — Sun, 08 Jun 2008 03:05:47 +0000

The Canadian and Ontario governments are now offering up to $10,000 in rebates when you improve the energy efficiency of your home. If you were considering an energy-efficient upgrade, this is definitely something you should look into.

The program is actually pretty simple—your house first undergoes an energy audit to determine what its “EnerGuide” rating is. It then undergoes another audit when the renovations are completed, and the rebates are issued based on the percentage-increase of the EnerGuide rating.

The audit itself also appears to be pretty straightforward—An auditor comes to your home and inspects your insulation, heating & cooling systems, windows, doors and water consumption. The audit should cost around $300, and the government will reimburse you 50% of the cost.

Fantastic opportunity… but do we qualify? According to the Ontario Home Energy Audit website we do:

If you live in Ontario and own a single family home you are eligible for the Home Energy Retrofit Program.

However all of the documentation is written for retrofits or renovations, and I can’t get a sense of their definition of “renovation” is.

Their FAQ says the following:

Are homes that are currently being built eligible for the programs?
No. New homes are not the program’s focus because they are already quite efficient.

The emphasis is mine, and clearly the answer is a bit grey. Our house isn’t “currently” being built, but it will be a “new home” when it’s complete.

So I’ve just stumbled on a potential gold mine… but I can’t tell if we actually qualify for it.

Update – I dug a little deeper and yeah, we qualify!

For more info about the program, you download a PDF here or visit any of these websites:

http://www.homeenergyontario.ca
http://www.ecoaction.gc.ca
http://www.oee.nrcan.gc.ca/corporate/incentives.cfm?attr=4#newhousing

SIPs 'n Sticks

jeremybell — Sat, 07 Jun 2008 02:21:35 +0000

SIPs, or Structural Insulated Panels, is another eco-friendly alternative we’re considering for this project. As you can see above, the concept is pretty simple—a layer of insulating foam is sandwiched between 2 pieces of structural board, which creates fully insulated and structual panel that is used in place of traditional “stick” framing.

According to the wiki, The primary benefit of using SIPs is their insulation properties, and their ease of installation:

When assembled, SIPs create a tighter building envelope and the walls will have a higher insulative value, which leads to fewer drafts and a decrease in operating costs for maintaining a comfortable interior environment for the occupants. Also, since SIPs work as framing, insulation, and exterior sheathing, and can come precut from the factory for the specific job, the exterior building envelope can be built quite quickly.

Apparently running electrical can be somewhat of a pain, however most SIP manufactures will pre-bore channels though the panels which make running cable easier. The panels can be quite large, so odds are you’ll need to rent a crane to aid in the installation process. However, the biggest drawback for us appears to be the lack of experience installers in Toronto. Our contractor has never worked with them, and we haven’t been able to get a clear estimate for installation.

That said, we’re talking with a few manufactures and we’ll see what the pricing is like. From what I can gather, the materials themselves will definitely be more expensive than traditional stick framing + spray foam, however I cannot get a sense of how much the labor savings will be.

Stay tuned.