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Posts Tagged ‘research’

Soil gas, radon and health

Sunday, May 16th, 2010
Written by Marcus de la fleur

I am moving down on my basement floor to-do list. The next task, the installation of the soil gas pipes, is all about health.

We spend the majority of our days indoors, yet we are not paying much if any attention to the health of those indoor environments. The indoor air quality (IAQ) of many work and living places is pretty lousy.

The green building movement is trying to change this by raising awareness of the IAQ issue. Poor IAQ can lead to low productivity at the workplace and health issues at work and at home. And we all know is that medical bills can be pretty expensive.

After having done some research on the radon issue, and after having decided that we will turn the basement into a garden unit, we realized that the installation of a soil gas pipe system for radon removal is an incredibly cheap IAQ insurance.

How does it work? I have four strands of 2 inch perforated, rigid plastic pipe traversing the basement. The strands are connected to a 4 inch perforated collector pipe.

The rigid plastic pipes collect any radon from the center portion of the basement. The perimeter drain, a flexible, perforated pipe, can collect any soil gas along the basement edge. If I connect it to the rigid plastic pipes it would perform double duty, keep the foundation wall dry (which also improves IAQ), and assisting with radon removal.

I like the idea of double duty and so I connected the 4 inch perforated collector pipe to the perimeter drain. The collector pipe lines up with one of our chimney flues, through which we can vent the soil gas removal system.

I prepared the chimney base, extended the collection pipe and left a stub to which we can connect the vent stack that will extend to the roof.

If I terminate the vent stack a few feet above the roof line with a material that readily heats up in the sun, I can rely on the negative pressure of the stack effect to draw soil gas out of the system from under the basement slab. I let thermodynamics do the work for me. I love it.

Tags: basement, green rehab, health, indoor air quality (IAQ), research
Posted in general construction | 1 Comment »

Zoning – the process

Tuesday, March 23rd, 2010
Written by Marcus de la fleur

The zoning issue we really have to worry about is the side yard setback violation. I learned during the initial review that we can apply to have the side yard setback reduced through a process called administrative adjustment.

Pre-application

I have to submit a site plan, building elevations, floor plans and a recent survey for review. The survey can’t be older than 60 days!

Since the last permit for our property was issued in 1960, I was asked to get copies of property deeds prior to 1960 from the Cook County Recorder of Deeds. The point of this exercise was to compare if the legal property description on the deeds matches with the current survey.

Equipped with deeds from 1954 and 1953 I went back to zoning for due diligence on property description and side yard setbacks. During that same review I was asked to remove the bathroom and front door from the basement. Because our plans show the building with two units, anything that may facilitate a third unit (i.e. a garden apartment in the basement) was not permissible.

A zoning officer wrote up the subject of the administrative adjustment (called written denial), which I have to get notarized along with a number of other forms.

Formal application

I was not happy! We thought about converting the basement into a garden apartment sometime in the future. Removing the bathroom and front door seemed utterly counterproductive. That said, I did understand where zoning was coming from.

Back home, I could not get myself acquainted with the idea of giving up the bathroom and front door. Instead, I took a deep dive into the zoning code. Lo and behold, I found article 17-13-1003-BB Additional Dwelling Unit:

“In the case of building permit applications for the repair, remodeling, and/or alteration of buildings that have been in lawful existence for 50 or more years, containing not more than 6 dwelling units, sought to correct Notices of Violation cited by the Department of Buildings, or for the voluntary rehabilitation of such structures, in which there is evidence that the building has been converted, altered or used for a greater number of dwelling units than existed at the time of its construction, the Zoning Administrator is authorized to approve an administrative adjustment to make zoning certification of the increased density, not to exceed more than 1 unit above its original construction, upon review of documented evidence supporting such increase in density.”

Great, if we already have to deal with an administrative adjustment, let’s see if we can add an additional dwelling unit to it!

I went back to zoning armed with a printout of the article and was allowed to add the third dwelling unit. We updated the written denial and I paid the $250 fee for the adjustment.

Notification of adjacent neighbors and the alderman

Next, I was handed three form letters that, as in the written denial, described the zoning changes (i.e. reduction in side yard setback at the back porch and addition of a third unit). The three letters went by certified mail to our adjacent neighbors and the alderman.

I received the delivery receipts of the letters to our neighbors within a couple of days. Not so for the Alderman. It turns out that the letter was delivered after business hours. The Postal Service left a pickup notice, which sat in the Alderman’s office for days. It was only after my probing that the letter was finally picked up.

To be fair, this time at least somebody picked up the phone, responded promptly to my request, and followed up with me!

Review period

With all three delivery receipts in hand, I went back to zoning and was asked to return in 15 business days.

The rule is that our neighbors and the alderman have 10 days to indicate any objections to our administrative adjustment. The Department of Zoning and Land Use Planning (DZP) has another 10 business days to process our case upon which a final decision is made.

Well, 15 days is certainly better than 20, but still, it looked like our permitting process was dragging on far longer than I had planned.

Tags: alderman, city of chicago, permit, research
Posted in permitting | No Comments »

Insulation – how much is needed?

Sunday, November 1st, 2009
Written by Marcus de la fleur

We figured out that insulating the building from the inside with spray polyurethane foam (or, in short, spray foam) is the most suitable approach. It avoids potential conflicts with our masonry shell and will help with the moisture management in the brick walls.

The next question is: how much insulation do we need? We can look at it in terms of R-value (thermal resistance) or the depth of the spray foam layer, although both are somewhat proportionate to each other.

Here is what the building code says: R-49 for ceilings, R-19 for exterior walls and R-10 for basement foundations (Chicago Building Code, Chapter 18-13-102.1.1; Building thermal envelope insulation, Table 18-13-402.1.1). The Chicago Green Homes program requires R-52 for ceiling, R-21 for exterior walls and R-15 for basement foundations.

Having our eye on the zero-energy goal, it appears that more insulation or the highest possible thermal resistance is better. But there are limitations we have to wrestle with.

To keep the moisture management of the masonry shell intact, the whole interior wall assembly must have a perm rate of greater than 1. Closed cell spray foam has a better thermal resistance than open cell foam, but also lower perm rates. Limiting the closed cell foam to a 1 inch layer followed by open cell foam should yield the right perm rate and allow for the needed diffusion of water vapor through the wall assembly.

And then there is the space limitation. The building originally had no insulation. There was the outside masonry shell, a ¾ inch furring strip, followed by a ¾ inch wood lath and plaster assembly, which we removed.

Replacing the old 1 ½” interior wall assembly with 1 inch of closed cell foam plus dry wall, would only give us an R-value of around 6.5. Adding more insulation, beyond the 1 inch, would take away from the room size. Here are some scenarios:

My friend David Lemair knew about our effort to balance room size with R-value and pointed me to an article in Fine Homebuilding. I learned that spray polyurethane foam has a point of diminishing returns:

“… you would think that an R-40 wall full of spray foam would perform twice as well as a wall sprayed to R-20 with the same foam, but that is not the case.”

Source: Yagid, Rob; Spray Foam – What Do You Really Know?; Fine Homebuilding, June/July 2009

The article goes on to explain that the increased effectiveness from the R-20 to the R-40 wall is only about 2%. Open cell foam apparently reaches its point of diminishing return at 5 inches, closed cell foam already at 3 or 4 inches. No technical explanation is given to what causes that diminishing return, but I would really like to know!

The puzzle is coming together. We have determined that the closed cell foam must be limited to 1 inch to keep the perm rate greater than 1. It looks like open cell spray foam has its point of diminishing returns at 5 inches. That would give us a 6 inch insulation assembly with an R-value of about 24 that takes 4 ½ to 5 inches away from the room size. This is a good balance between R-value and room size.

Tags: insulation, layout, research
Posted in design | 6 Comments »

Insulation – which material cuts it?

Monday, October 26th, 2009
Written by Marcus de la fleur

If you have followed the previous posts about the insulation conflicts and moisture management issues, you may ask why not go simple – skip insulation altogether and just have brick wall exposed on the inside. A very tempting thought, isn’t it? It would look pretty good and we could avoid all these problems.

But we also would create a big problem. A three wythe (or 12”) thick brick wall may have a R-4 value. The air film on the wall would give me another R-1, totaling R-5. That is if the brick is dry. If it is wet, these values will drop. A decent window may have a better R-value than the brick wall! We need good insulation, if we want to have a decent shot at our zero-energy goals.

There is quite a variety of materials to pick from, starting with the very common fiberglass batts, the more expensive rigid foam boards, or materials with high recycled content such as blown-in cellulose or recycled cotton batts.

Understanding the limitations and opportunities that come with our masonry shell, and having distilled two key principles, the choice actually narrows to just one material: blown-in foam insulation.

“A low[…] risk approach to interior masonry retrofits that has been used for several years involves spraying an airtight insulating foam directly to the back of the existing masonry [shell].”

Reference: Building Science Digest 114 (Interior Insulation Retrofits of Load-Bearing Masonry Walls in Cold Climates)

Also known as spray polyurethane foam (or in short: spray foam), it would eliminate air gaps and air leakage if applied across the entire interior shell, including the roof. Basically, it would give us an airtight building envelope and act as a moisture barrier (or vapor retarder) helping with the control of incidental rain penetration.

A Building Science publication (Building Science Digest 114) explains spray foam rationales and choice in detail and is worth while reading.

Because spray foam is semi-permeable (a vapor retarder but not a vapor barrier), it will allow moisture in the masonry shell to diffuse to the outside and in. I have to make sure that the perm rate of the entire interior wall assembly is greater than 1 – and we are all set!

There are two kinds of spray polyurethane foams out there:

Closed Cell

As the name suggests, each little cell (or bubble) encloses an air pocket, forming a monolithic airtight layer at an R-value of around 6.5 per inch. Most closed cell spray foams have a density of about 2 pounds per cubic foot (pcf) and have a low diffusion or perm rate (around 1 to 2 at 1 inch thickness).

Open Cell

This foam is much lighter at a density of 0.5 pcf and forms more of a web structure. It is still considered airtight if applied at a depth of several inches. The R-value for open cell products hovers around 3.5 per inch. Water vapor can diffuse freely through the material.

The one disadvantage of spray polyurethane foam that is often mentioned is cost. And yes, it is much more expensive than your typical fiberglass batts – closed cell more so than open cell, because it requires more material. Plus, it needs to be installed by a trained professional.

6” of fiberglass batts (around R-19): $0.30 to $0.60 per square foot (material only)
6”of open cell spray foam (around R-21): around $2.50 per square foot (material and labor)
6”of closed cell spray foam (around R-39): $5.00 to $6.00 per square foot (material and labor)

We would pay more – and that is fine – because we will get more. With spray foam, we don’t have to worry about air leakage, condensation and potential mold problems, or diminished R-values. Instead, we get the airtight building envelope we need, and lasting R-values. If we would try to accomplish the same results with cheaper insulation materials, we probably would, in the end, pay as much.

A drawback that I still debate is that spray polyurethane foam is a petroleum based product. The good news is that most spray foams are now VOC (volatile organic compounds) free, using water as their blowing agent. Some products are marketed as green because of some soy based oil content. That overall content is, however, relatively small, plus I am not sure if I would accept soybean farming as a sustainable practice.

Another unanswered question that keeps me pondering has to do with the end-of-life use. There is no known recycling option or second use for this material. If the spray foam ever gets torn out, it is likely to end up in a landfill. The only conciliation I have is that it should serve and maintain its performance for several generations.

More info on spray foam:

What is:

Air barrier

Moisture barrier: See references below to vapor barrier and retarder.

Vapor barrier and vapor retarder

Additional resource: Consumer’s Guide to Vapor Barriers at the U.S. Department of Energy

Tags: construction waste management, cost, economics, insulation, recycling, research
Posted in design | No Comments »

Insulation – starts with moisture management

Friday, October 23rd, 2009
Written by Marcus de la fleur

Following up on the previous post, common brick, like in our building, is very pervious to water. If adding insulation to a storage or mass wall system, such as our brick shell, one of the issues is condensation and potential freeze-thaw damage to the brick work. Insulation on the inside of the building can lead to condensation and interrupts the heat transfer into the masonry shell during the cold season. As such it is very likely that the shell will go through more freeze-thaw cycles than ever before.

“Freeze-thaw damage […] require the material to be at or near capillary saturation (100% Relative Humidity)”

Reference: Building Science Digest 138 (Moisture and Materials)

“Driving rain is typically the largest source of moisture for the above-grade building enclosure”

Reference: Building Science Digest 013 (Rain Control in Buildings)

The removal of water from our brick shell, or keeping the rain out, is – let’s say – rather important to its performance and integrity. It comes down to a balance of moisture storage capacity versus drying capacity. So, how does water or moisture move through a brick wall during wetting or drying?

I had to re-learn some basics of water and its various states (solid, liquid, vapor and adsorbed). The liquid and vapor states appear the most relevant. The former is pretty straight forward – or for that matter straight downward, controlled by gravity (water flows/drains downhill).

Good detailing can prevent rain from entering the storage or mass wall system and help with the balance between wetting and drying. This includes tuck pointing, drip edges, and the right flashing details, particularly around windows and in corners. Rain deflection through overhangs is another strategy.

“It should be clear that drainage is not sufficient for this purpose since it will leave large amount of saturated (100% Relative Humidity) material. Capillary and absorbed moisture can only be dried by evaporation followed by diffusion.”

Reference: Building Science Digest 138 (Moisture and Materials)

We are now talking about water vapor. Its movement is governed by three rules:

Water vapor in the air moves from high pressure to low pressure areas.
Water vapor diffuses through permeable materials from warm to cold.
Water vapor diffuses through permeable materials from areas of higher concentrations to areas of lower concentrations.

As part of the drying mechanisms, I have to allow water vapor to diffuse out of the wall, whether towards the inside or outside.

In the summer, water in the brick tends to diffuse to the inside of the building, following the thermal and concentration gradient. Whatever kind of insulation system I decide to use, it is important that it allows for that inward driven moisture (water vapor) to pass.

“Rule Number One: Never install a vapor barrier on the inside of a wall assembly, which has a moisture reservoir cladding…”

Reference: Building Science Digest 108 (Investigating and Diagnosing Moisture Problems)

If moisture cannot pass, or if I add a vapor barrier to the interior wall assembly, summer moisture will condense in the wall assembly. That is a perfect recipe for water damage and mold growth – something our building has already seen in its past.

During winter, vapor tends to diffuse to the outside – again – along the thermal and concentration gradient. That vapor may have its origins in high Relative Humidity levels in the living spaces. The insulation I plan to add to the inside will reduce the temperature along the interior masonry shell. Inside air diffusing outwards and coming into contact with the cold masonry face could condense.

“Given sufficient air leakage and sufficiently high indoor Relative Humidity this condensate can accumulate faster than it can dry, and the interior face of the masonry will become saturated.”

Reference: Building Science Digest 114 (Interior Insulation Retrofits of Load-Bearing Masonry Walls in Cold Climates)

This in turn can create the potential for freeze-thaw damage.

Using insulation that can eliminate any air gap or air leakage with an airtight layer along the masonry shell should prevent condensation and subsequent freeze-thaw damage. But it still has to allow for vapor diffusion during summer (see above).

Confused? I don’t blame you! It took me a while to wrap my head around this. Eventually, I was able to boil it down to two key principles that I can use:

The insulation will need to eliminate air gaps and needs to be air tight to eliminate air leakage driven condensation in the winter.
The insulation will need to be permeable to water vapor for inward diffusion and drying during summer.

Tags: drainage, insulation, research, water
Posted in design | No Comments »

Insulation – lots of conflicts

Tuesday, October 20th, 2009
Written by Marcus de la fleur

Sometimes coincidence is your savior. I discussed our brick work with Martin Bazula, a restoration mason here in Chicago, and shared our goal of super-insulating the building – from the inside. Martin paused, thought and proceeded to explain to me that these old common brick walls were not intended to be insulated. In fact, the absence of insulation is somewhat their lifeline, helping with rain water and moisture management on and in the wall, and reducing the number of freeze-thaw cycles.

I almost had kittens! We finally found our dream home with a masonry shell. I already gave up the idea of insulating from the outside. And now I learn that the masonry shell, which was so important to us, may not be compatible with our insulation goals and ultimately the zero-energy objective!

Did you think that brick is impervious to water? Think again! Common brick is a like a sponge. Did you ever notice how masons dump or soak brick in water before they lay it? That is to prevent a dry brick from sucking all the moisture out of the fresh mortar during the curing process, which may lead to cracks. Plus, the mortar joints are also porous and act like sponges. So how do these brick walls, such as ours, help with the rain control and moisture management?

It actually is one of the oldest strategies out there. The Romans used it. It’s called storage or mass walls.

“This approach requires the use of an assembly of materials with enough storage mass and moisture tolerance to absorb all rainwater that is not drained or otherwise removed from the outer surface. In a functional mass or storage wall this moisture is eventually removed by evaporative drying before it reaches the inner surface of the wall. “

Reference: Building Science Digest 013 (Rain Control in Buildings)

The challenge of insulating such storage or mass walls, which Martin Bazula pointed out to me, was confirmed in another article I researched:

“Adding insulation to the [storage or mass] walls of such masonry buildings in cold, and particularly cold and wet, climates may cause performance and durability problems in some cases.”

Reference: Building Science Digest 114 (Interior Insulation Retrofits of Load-Bearing Masonry Walls in Cold Climates)

Great! What’s next? I hope a solution to this problem!

You can contact Martin Bazula at mbazula@hotmail.com

Tags: insulation, research, water
Posted in design | No Comments »

Insulation – how it started

Tuesday, October 13th, 2009
Written by Marcus de la fleur

Our two key goals are super-insulation (high R-value) and air-tightness (elimination of leaks and drafts). Simple enough, isn’t it? To my surprise, this issue got me deep into rocket science. There was a very steep learning curve and my ideas and aspirations on insulation options had changed several times over the past year based on emerging facts and realities.

While we were house hunting, we were only considering buildings with a masonry shell for the structural and longevity aspects (see also “Dream home wish list” post). Another idea of mine was to use the masonry building shell as thermal mass by leaving it exposed to the interior and applying the insulation on the outside.

Fast forward. We now own our house with typical Chicago common-brick side elevations and an ornate front elevation. Our dream of exposed interior brick walls radiating warmth appears to materialize. To get there, we will need to super-insulate the building from the outside. I began to research our options, and ran into a brick wall (pun intended).

Do we really want to hide our ornate front elevation behind insulation? Of course not! We would insulate the front from the inside – and would be left with big thermal bridges to the left and right. Not good.

Then there is the dimensional issue. Portions of the west side of our building are almost on the property line. We would encroach into our neighbor’s property if we began to insulate on the outside of these wall sections.

How about insulating portions on the outside and others on the inside? Not only is this getting really complicated, but I end up with a whole bunch of thermal bridges that would defeat our insulation goal.

And, of course, there are code issues to contend with. Chicago common brick has an excellent fire rating. Whatever I would use to cover the outside insulation will have to meet the one-hour fire rating requirement.

Most innovative ideas start with an uphill struggle. If we really pushed it and worked long and hard, we possibly would find a way to make it work. The question is: Is it worth it?

I talked with a lot of friends, contractors and green building professionals and did not receive any encouragement for my idea – absolutely none. Nor did I find any supporting clues in my research. The consensus was that insulating our building from the outside was too resource intensive and expensive to justify any thermal mass benefit in the interior – thermal mass we may not even need with a super-insulated and airtight envelope.

Time to hit the reset button! How about insulating the shell from the interior? But what would be the best material choice? And how can we do this without compromising the integrity of the 100+ year old Chicago common-brick walls?

Tags: cost, economics, house hunting, insulation, research
Posted in design | No Comments »

Dusting off the wish list

Thursday, September 3rd, 2009
Written by Marcus de la fleur

We are anxious to start with the design, which will lead us to plans and specifications and ultimately to our green building permit. We have been deconstructing for a while to (hopefully) uncover all problems and develop an inventory of what needs to be fixed.

Interestingly enough, most problems we unveiled during deconstruction were water related: The damage to framing in the basement (see 04/23/2009 post), the jungle of existing and abandoned utilities (see 05/28/2009 post), water damage in the bathrooms (see 08/01/2009 post), a disintegrated roof drain (see 06/09/2009 post) and the mystery of the missing cold water line (see 06/22/2009 post).

We’ve begun to have a pretty good idea what the green rehab will involve. This is a good time to go back to basics – to revisit our project principles and take another close look at our wish list. I am talking big picture here, looking at the goals of resource efficiency and zero energy. I am not ready to get distracted by low flow water fixtures and LED versus CFL’s. Rather, I have to think about big ticket and building related items such as the envelope and energy sources:

Super insulated and airtight building envelope, that helps us with reducing our heating and cooling needs. We intend to get away without central air conditioning.
Solar hot water system for space heating and domestic hot water. We should be able to downsize the solar hot water system, because of the super insulated and airtight building envelope.
Cast iron baseboard radiators for space heating. We are concerned about overheating the interior because of all the insulation and think that the small size of the baseboard radiators may prevent this.
Biomass backup furnace for those stretches of overcast days in November and December when the solar hot water system needs some help.
Passive ventilation systems to keep the air fresh and healthy in our airtight envelope.
Heat recovery system for ventilation. We want the stale air out, but would like to keep the energy in (warmth or coolness).
Sunroom for preconditioning. Our back porch faces south and we have the dream to convert it into a four seasons or sun room that can preheat or precondition the air for the rest of the building during the cooler months.
PV array system with battery backup for electricity production, which should help with our zero energy goal and small carbon footprint.
Wind turbine for electricity generation.
Vegetable garden on the roof, which will help with the longevity of the envelope (in this case the roof), help with insulation (particular with the heat gain), and provide fuel for us, the inhabitants of the structure.

This sounds all very good, but we have to start separating the wheat from the chaff. Do these wish list items actually make sense? Do they fit our budget? Will they work together as a system and get us to zero energy, or will they be counterproductive? We have to find out through more research and the design process.

Tags: green rehab, green roof, research, water, wish list
Posted in design | No Comments »

We had a pantry - once…

Wednesday, June 17th, 2009
Written by Marcus de la fleur

Today’s report is about another of our more interesting discoveries.

Some things left us scratching our head while looking at the various rooms prior to any deconstruction. Take the bedroom in the back, next to the kitchen, for example. It has a more or less a square footprint with that odd closet sticking out in one corner (just ignore the salvaged casings in trims in the picture below…).

pantry-01

Looking at the overall floor plan composition and architectural style of this house, this bedroom layout with the closet did not seem right. And it wasn’t! While taking the adjacent kitchen apart, we discovered a walled over doorway, leading into that bedroom.

pantry-02

Looking at it from the other side, the bedroom side, we did not only find that same door, but also plenty of evidence of a wall that must have been removed some time ago. The hardwood floor, for instance, stopped at either side of that former wall, and so did the wood lath in the ceiling, where the studs would have been.

pantry-03

Putting one and one together, we concluded that we found the former pantry that connected to the kitchen. Question is now: what are we going to do with it?

Leaving the bedroom floor plan as is, is out of the question. The wall that once was, has to come back. We could, in other words, restore the pantry, although the kitchen is already very large and offers a lot of storage possibilities. May be we can turn this into a half bathroom?

Tags: deconstruction, images, layout, research
Posted in deconstruction | No Comments »

Rediscovering our living room – Part 2

Monday, June 15th, 2009
Written by Marcus de la fleur

Yep, there was more to discover. Look at the door to the very left in the picture below. That is a very odd proportion for an entry into such a grand living room, now that we know about the archway (see also 06/13/2009 post).

living-2-archway-b4

The corridor leading to that door also didn’t make any sense at all. What’s the point of stepping through the front door into a small vestibule, and then into a dark, 12 foot long corridor with a small door to the side at the end?

living-doorway-0

I had difficulty to believe that an architect a hundred years ago would have included a space in a house that basically served no function.

It turns out that the oddly proportioned door was not original but added sometime later. And here’s the kicker. Look carefully at the living room wall below, and you may detect an interesting outline.

living-doorway-1

Behind that outline, we found a glorious double door entry way that once led from the corridor into the living space. Much better proportioned, wouldn’t you agree?

living-doorway-3

The functionality conundrum of the corridor is resolved too! In the corridor, to the left of the double door entry way, was once and walk-in closet for coats etc. Or – if you look at the picture below, the closet would have been at the very end of the corridor.

living-doorway-4

That closet had been removed once the new, oddly proportioned door was added. And why would someone remove that closet, add an odd door, close up the double door entry way and wall off the grand archway (see also 06/13/2009 post)? Well, to split the very large living room into two spaces, adding a front bedroom to the unit. Apparently not that uncommon in Chicago’s graystone and brownstone buildings.

It’s a real thrill and treat to discover the original architecture and layout and dream up plans about bringing it all back.

Tags: deconstruction, images, layout, research
Posted in deconstruction | 2 Comments »

Posts Tagged ‘research’

Soil gas, radon and health