Let’s get complicated for a minute. Insulation. What’s complicated about insulation – throw some in the walls and ceilings to meet code, seal it up and you’re good to go right. Wait. Firstly, insulation may be one of the most important components or systems in the home but unfortunately it is behind the walls so you don’t get to stare at it when the house is done, nor do you get to see how it was done…

There are lots of useful website resources to explain insulation types and applications but there are some important concepts that are sadly missed or difficult to locate. Starting with the current and legacy system of insulation in the market – typical pink fiberglass batt and the R-Value.

Idea 1 – R value
Current code in our area requires at least R20 walls and R40 ceilings that will be exposed to the exterior. Traditionally insulation was measured with an R value – the result of a test where a sealed box without studs is lined with insulation and tested to see how long it takes for the temperature inside to change to a warmer or colder exterior temperature. Simple.

The problems with this system as it relates to the use of insulation are many but here are a few main that make the test useless when gauging insulation performance in a practical context; the box doesn’t account for air movement caused by wind or air pressure differences between in and out, introduction of lesser R-value materials like wall studs, leaks or openings in the box envelope to the exterior such as around windows and doors or the biggy, insulation settling over time. It just looks at insulation in a perfect and isolated context.

Idea 2 – Application
Like many materials, the issues with performance can come down to the details of installation and use. That doesn’t apologize for the material in this case however because in reality – this material is designed to fail because it’s a terribly outdated system. During install, the format standards associated with the product have it fit into the gap between studs as we all know – and this fit is relatively snug, enough to support the material most times but the flexibility of the material and lightness means it doesn’t really hand on and is to some degree supporting itself like a post using whatever tensile strength it has. The ends are cut by the installer and are sometime short or long – they are working fast. In the end the batts go in nearly even and almost the right length but there are gaps, lots and lots of gaps. Remember your R Value was 20 in a perfect sealed box – what do you think you have now.

Next remember that the insulation is trapped between studs that are approximately 2” thick and depending on construction method, 6” deep and extend all the way to touch the uninsulated external wall’s interior surface. This means that these studs will be making a conductive connection to the outside world. Studs when measured for R value are said to be approximately R 4 though I’ve seen estimates as high as R 7. None the less, when you add up the amount of studs per square foot, as well as account for all the gaps – between studs and around windows and doors – you end up on average with R 10. What? R 10? Yep.

Idea 3 – Settling and performance
So the vapour barrier goes on and next the drywall and you move in. Over the next few years, the insulation settles. You may have done a reno or two in your life and have seen this big gap at the ceiling when you ripped the drywall off the walls. Yes, a big 12” gap where the insulation sagged from it’s own weight and shrank to reduce the coverage in the wall by as much as 1/8th on an 8’ wall. But does this mean this reduces the performance of the insulation by 1/8th? No, a 1/2” hole in a 10” balloon doesn’t reduce it’s effectiveness proportionately – it fails badly and lets all the air out. And this is what happens to your house – the balloon lets out all the heat from where heat rises – to the ceiling where the walls intersect the ceiling.

Idea 4 – Health
Why is this always last – why does health not have an ROI? Well for us it does and this is why. Once fiberglass insulation starts sagging and air starts passing through the envelope in both directions due to warm air trying to get out or external air being sucked in to replace air whipping out your ceiling or out your hood fan – dirt, dust and organics move through the insulation in both directions – trapping these organic particles not to mention pulling free glass particles into your breathing air. Eventually tears and gaps in your semi permeable vapour barrier (clear poly) allow moisture to enter and get trapped, condensing in cooler areas and when mixed with your dust and organics, creates mold and lots of it. Next, you breath the mold spores which leads to one of the largest interior air quality issues of homes today.

So, not so simple after all. And worth considering. There is a great solution and that’s blown foam. Now nothing is without disadvantages but that’s for another post. Concentrating on only the advantages – blown closed cell foam solves all those issues. In brief the R Value is measured the same but in reality it can be measured using a performance value as a percentage of R. to illustrate, pink insulation has a performance of 40% – it sagged, installed poorly, was porous, had gaps and arrived at less than half of the rated R value. Blown foam is rigid and stays inert for the life of the home while also sticking to and filling all gaps, expanding into any place a vapour of the insulation can get to before expanding. The subsequent finished performance is 95+%, for good. What this means is that if you believe R 20 is an acceptable value to achieve an R 10 in practicality – than in foam the equivalent R 20 depth of insulation will have and R 40 practical relative performance rating. It’s twice as good.

Following that, the foam is a vapour barrier once hardened if not scraped so once a 6mil poly is applied on top, there is very little moisture passing in either direction. Also, since the foam makes a mostly air tight seal, little to no air moves reducing the chance of organics contacting your drywall and creating mold situations – foam cannot support mold growth.

Other benefits are the high acoustical insulative properties that make a home simply the quietest on the block improving your enjoyment and sleep – oh, and did I mention you’ll save a lot of energy. The no VOC after curing, inertness of the material and high energy rating also make it qualify for LEED points.

For our home we chose to go with closed cell blown expanding foam – R 28 in the walls and R 40 in the ceilings. The application is now almost complete and we’re ready for careful vapour barrier application and drywall next week.

Supplier – Jarvis Insulation
The Jarvis team has operated in our area for a couple of generations and has a solid reputation for all types of applications in commercial and residential. Though they would be primarily using traditional insulation, Dave Jarvis has studied insulation methods and materials extensively and tries hard to convince customers that blown foam is where it’s at for all the reasons above. He admits that the price is a barrier of entry for a lot of people but that more and more are making the informed switch. While evaluating contracts from various suppliers, we heard more than a few times that Jarvis was the most knowledgeable and qualified to blow foam in our high performance house and would provide the best guidance and value. This has indeed been our experience.

The foundation walls are also sealed with Watchdog Waterproofing making them impervious to moisture. The combined system apparently provides a thermal break of R12 from the grade down. This combination should guarantee the basement is dry for at least 10 years. What? Only 10 years? This is the sad state of basement guarantees – if you believe you’re about to get better, read the fine print.