Of Black Locust, Joinery, and Sweat

At long last the renovation to glass in the verandah has begun. I found a skilled carpenter willing to work with me who could find a source of locally harvested black locust timbers. This wood is highly rot and termite resistant.

Insulative strips for the slab.

Insulative strip, foam insulation, and flashing.

Before...

During...

The first step was to dress the slab for enclosure. As this space will be expected to provide lots of solar gain in the winter to heat the house and help propagate plants, the slab needed to be insulated, where possible, to break the thermal bridge which would rob the space of heat. I fashioned strips of blue foam insulation, scavenged of course, with 3/8 inch exterior plywood glued on to provide a rigid and protective surface. We painted them up, see the previous post of Jacqui painting the last ones in the midday sun. These were then screwed onto the slab using tapcon screws. Over this we laid a thin strip of foam insulation, found in my father's garage, and then metal flashing with a drip edge. On top of all this we placed the 6x6 posts and a 2x6 sole board to form the base for the windows.

Of course we first removed the old posts which happened to be filled with wasp nests. I was stung the day I removed the step railings, and being somewhat allergic, I swelled up, flushed and went all woozy for the rest of the day. So unfortunately the wasps had to go. We had been co-existing rather peaceably with them since we moved in, but they wouldn't tolerate this level of disturbance, and I couldn't tolerate multiple stings. We sprayed them with dish liquid and smashed the ones that persisted in returning. OM MANI PADME HUM for the wasps. May they be reborn quickly!

Framed for windows.

Pretty, but not ready for sealing...

After the posts and sole boards were in, we measured the windows and framed in the openings for them. They won 't be installed until the wood has a chance to dry thoroughly and gets a coat of finish/ preservative.

We haven't finished the framing because some of the wood we had drop shipped to us was unacceptable, and we are waiting for replacements.

No more steps! We'll have to walk around now.

We also took this opportunity to get started on the deck that will go over the rainwater tanks. As the tanks will be in the way for the initial ledger attachment, we decided to get it done now. Tomorrow we hope the grading will take place for the tanks. This necessitated removing the east steps.

And oh yes, it was hot and humid, and we sweated buckets. The heat index was 99 degrees today, going up to 109 degrees tomorrow... a rest day! Welcome to the south in the summer.

Household efficiency skyrockets while bank account plummets!

Just in time for the first days of summer, we have FINALLY  addressed two very important efficiency issues on the house at The Sustainable Living Project. In the last 2 weeks we have had our walls insulated, a process of drilling holes through the indoor plaster and blowing it in, as well as a new reflective metal roof installed over a layer of 1" foam insulation.

The walls; our brick walls get full sun for most of the day and that heat was going straight into the interior plaster, which is about 1" thick, and thence into the house. We shopped around for contractors, looking specifically for someone to use cellulose insulation as that is not only more sustainable but also less toxic. Not a single one would use it! They all use fiberglass. As the walls are sealed I believe we are avoiding exposure to the fibers, which have recently been listed by the EPA as a carcinogen, but we had to compromise on the sustainability aspect.

Being on a tight budget we have long ago reconciled ourselves to compromise when it is necessary. One of the rationales in this case is that the material is going to help us reduce our use of fossil fuels by improving the thermal efficiency of the house. Over time we hope this savings will offset the damage done in the manufacture of the less sustainable material.

On the North side, insulation first, metal on top, good riddance to the asphalt!

The roof, as with most homes here and all over the south, was covered in dark asphalt shingles applied directly over the wood sheathing. These shingles act like a massive thermal collector and the heat is passed directly indoors. In the summer heat this is lunacy! We have been planning to address this serious design flaw for some time but again, it took a while to find a contractor we were comfortable with that we could afford. He had never put a residential metal roof over insulation but was willing to look into it. After some consultation he determined that it would not void any warranties. But alas, again we compromised, going with his recommendation of foam insulation rather than a natural fiber board. This has several advantages, it is lighter, will not absorb moisture, and could be installed over the existing asphalt shingles. We really did not want to disturb the existing roof as the ensuing mess in the yard, where we grow our food, would have been quite toxic. So essentially these toxic petrochemical roofing shingles are now encapsulated under the new roof. And yes the same compromise principle applies, these materials will last a long time and will reduce fossil fuel use for their lifetime.

And oh what a difference this has made. Normally the upstairs renovation is 15º to 20º hotter than the downstairs. Now at most it has been 5º warmer. When we got up this morning, the outdoor temp was about 68º while indoors it was 74º. We embarked upon our usual practice of aggressive ventilation during the cool hours of the morning. The temp held firm at 74º. I believe this was due to the outdoor temp staying relatively cool for most of the morning as it was raining. Eventually the temp indoors dropped to 73º and later, as the outdoor temps got up to near 88º with full sun, our indoor temp rose to 75º. When I cooked a zuchini casserole in the oven at the hottest time of day the indoor temp climbed to 77º downstairs and up. I'm stoked! Essentially we've changed the way the house responds to temperature changes, slowing down it's response. This is good, as the indoor temps will likely be at their highest in the evening when the outdoors is cooling off we will be able to draw that cool air into the house to drop the temps which will continue to drop through the night as the walls will not be collecting heat from the exterior bricks. I'm betting we will not need the AC at all now. Additionally, in the winter the extra insulation should drastically reduce the amount of wood we need to burn to stay warm.

So far so good, but tomorrow, the solstice, the temps are supposed to reach into the low nineties. That'll be the real test.

the south side

Insulation -Just do it!

Here's the next installment from my articles for the Sheffield Star green pages.

As I said in my last post, insulation is essential. Once you have addressed air leaks your next best investment will be insulation. Primary areas to insulate are the loft, the walls, and the floor. If you are re-roofing be sure to get a layer of insulation installed under the tiles. This may need an air gap between it and the tiles as well. Additionally, you should insulate any hot water pipes that you can get to.

The Loft - If a loft renovation has been done and the actual flat space above the ceiling is minimal then doing more than 10 to 16 inches may not be worth it as the pitched portion of the roof will be the largest area of loss. If you are planning a loft renovation be sure to plan in a method to insulate the entire roof area. One solution is insulated drywall for the pitched sections, to avoid losing too much headroom, and at least 10 to 16 inches of recycled denim or cellulose insulation in the flat section. If you have a large flat area consider going up to 24 inches of depth for best performance. Be sure to fill all gaps while still allowing for eaves ventilation and cover the ceiling joists. Make sure you insulate all the flat spaces at floor level that are sealed off behind new walls. Typical payback periods for loft insulation will be short, particularly if you do it yourself or get a grant for it, in some cases as little as one winter.

The Walls - Most walls in England, particularly in older homes are stone or brick. Most brick walls built since the turn of the century, 19th to 20th, are built as two walls side by side. These are known as cavity walls. Stone walls, while thicker tend to be a single layer or solid.

Grants for cavity wall insulation are available and well worth the effort to get. Cavities should be filled with a waterproof insulation and due to the nature of the job will likely need to be done by a qualified contractor. If you are doing a renovation, have a look at your lintels. A single stone or concrete lintel that spans the cavity will act as a cold bridge, draining away heat from the inside. Plan to replace the single lintels with separated lintels.
If you have solid walls there are two options, insulate externally or insulate internally.

External, though more expensive, can be breathable and will allow the internal masonry to act as a heat store, known as thermal mass, and will not reduce the interior space. It will however change the appearance of the building. There are other issues with external insulation that you don’t face with internal. Roof overhangs will need to be addressed to insure that the top edge of the insulation is covered. A good time to do an external insulation job might be when you are replacing the roof. Also, external plumbing, guttering and wiring will have to be removed and rerouted afterwards to accommodate the extra thickness.

Internal insulation, typically achieved through the addition of a layer of insulated drywall, will require removal of floor and ceiling molding, skirting boards, and the remounting of electrical fixtures and outlets. Ideally, it should happen as you are installing double glazing as you will want to insulate reveals and lintels as well. It also means that you will lose interior space, in a small victorian terrace this may be a high price to pay. But this method will cost less than exterior insulation and can be accomplished on a room by room basis. Unfortunately, it will reduce thermal mass and won’t address cold bridging from external to internal walls. As you will be reducing the breathability of the walls you may encounter damp problems which can be addressed with a vapour barrier on the warm side of the insulation.

The Floor- While not the first priority for insulation as it is only responsible for up 20% of heat loss, once the loft is insulated and the cavity walls have been filled it is well worth doing. Plan on at least 8 to 10 inches of insulation between the floor joists. This is usually easily achieved in a a Victorian era house with a cellar. If you are doing a major renovation and replacing the floor be sure the insulation overlaps the wall insulation if internal.


References:
Harris, C. and Borer, P. 1998 - The Whole House Book; Ecological Building Design and Materials 2nd edition

Benefits of air sealing and insulation

As I am in the middle of my series on green refurbishment of domestic residences for the Sheffield Star online green pages I have been keeping an eye out for relevant posts on my favorite blogs.

I've emphasized the importance of air sealing your house in these posts,

Post #7 Keep the cold out and the warmth in
and

Post #8 It's Cold Outside

I've started discussing insulation in this post,

Post #9 Insulation basics

Barry Katz over at "The Future is Green" blog has put up an excellent post on these topics and specifically covers payback periods on these simple, inexpensive, DIY technologies.
Here's an excerpt,

"Air-sealing and insulation can pay for themselves in as little as two years, and continue to pay dividends in the form of lower fuel bills.

Another advantage of upgrading our aging housing stock is that unlike the vast tracts of suburban sprawl that characterize new residential construction, older homes are often located in compact, walkable communities.

Revitalizing such neighborhoods strengthens a pattern of development that is far less dependent on the automobile and is therefore more sustainable." - Barry Katz

Sheffield Star online post #9, Insulation basics

Insulation is essential! I can’t say it any plainer than that. You wouldn’t step outside on a winter morning without your cardigan, that's a sweater for all you stateside readers, would you. So why leave your house to pour heat through the loft (attic), walls, windows, and floors?

The choice of insulation is important. Here are a few questions to consider when choosing insulation products.
• Is the insulation going to make you sick?
• Does your choice of insulation use too much energy to manufacture and require too many resources dug from the ground or pumped from oil wells to produce?
• Is the product recyclable or biodegradable?
• How effective is it?

Products like mineral wool and spun fibreglass consist of fibres that are easily inhaled. Much like asbestos fibres they can lodge in the lungs and may pose a health threat. These products also typically use a resin based binder to hold them together. Like most resins they are manufactured using petrochemicals and have a negative impact on indoor air quality. In some cases, like formaldehyde, these resins are known to cause cancer. These products are not generally recyclable and pose contamination risks at disposal. Because they rely on mining and industrial processes to manufacture they require more energy, embodied energy, to produce than more natural alternatives.

The manufactured or blown foam products also require massive inputs of chemicals and energy to produce. They are not recyclable and present similar if not worse disposal problems.
These concerns have to be balanced with the benefits of using some of these products. In some cases they are the best alternative, as in blown foam to seal and insulate cracks and gaps around pipes and wiring in walls or around windows. There are more natural alternatives however for almost all of the above mentioned products. For instance a blown foam product that is soy based has recently been developed.

For loft and under floor insulation, the more green options are natural fibres such as wool or hemp, and recycled cellulose or fabric fibres. Another option is cork, a product sustainably harvested from trees. Cork can also be used in cavity walls as it is waterproof as well. All these products are recyclable and have low embodied energy.

Effectiveness, measured in U-value, or R-value for those in the states, varies from product to product. For U value the number should be lower as it is a measurement of how much heat passes through the material whereas for R value the number should be high as it is a measure of who well the heat is blocked. Check it out before purchasing as a product that has half the effectiveness compared to another will require twice as much to achieve the same end.

I'll do another post where I’ll cover specific strategies for insulating your home.