Tag Archives: indoor air quality (IAQ)

1st floor priming

Our freshly restored hardwood floors are all carefully covered up, because its time to start painting.

There are two components to this task: the straightforward and the not so straightforward parts.

Getting the paint on the wall is what I would call the straightforward part. Actually, we won’t start with paint. We’ll start by priming all the drywall.

The not so straightforward part has to do with the product choice. We are set on zero VOC primer and paint products. This is non-negotiable, as it has an direct impact on the indoor air quality (IAQ).

Back when we painted the garden unit, I sourced the primer and paint from the Chicago Green Depot, which has gone out of business since. With that, I lost a convenient and affordable source for zero VOC paint products.

“No problem, there must be other products and suppliers.” Yep! But few of them are conveniently accessible (i.e. brick and mortar business), and even fewer have zero VOC products at a reasonable price point.

I mean, if you look around and online, you can find coolest products under the sun out there. But we are not about to spend $60, $50 or even $40 per gallon for paint or primer. Our threshold is at $30/gallon, or preferably less.

That really begins to narrow it down!

For the primer we settled on Bulls Eye Zero Primer-Sealer by Zinsser. Even though it is water based, it has a really thick consistency – almost too thick. We diluted it to the maximum recommended ratio, and it still was thick, but we were able to get a few additional square feet of coverage out of it.

Thank you to our dear friends Scott and Carlos who master roller and brushes like few others do!

Putting it on

Once we decided what floor coating to use and once it was purchased, it was time to put in onto our spanking new looking old hardwood floors!

I had read the installation instructions, which asked for thorough dust removal prior to the sealer application. I started by sweeping all the floors, followed by meticulous vacuuming with our big shop vac.

That didn’t stop our contractor from vacuuming again in preparation for the first coat application.

Did I mention that the sealer was literally odorless, despite the 200 g/l VOC content? If you ever have been around the high VOC content products, you’ll appreciate the absence of fumes and the improvement to indoor air quality (IQA).

The day after the first coat, Frank, our flooring contractor, buffed all the floors with a fine 200 mesh. It was explained to me that the first coat typically raise the wood grain. Thus the buffing to smooth everything out again.

The buffing and vacuuming was followed by a second coat of the sealer, which was evenly applied across the floors.

This is all deadline work because we are using a two component based product. Once the catalyst (or hardener) is mixed in with the sealer, things have to move at a good pace. The working time of the Arboritec Avenue floor finish is limited to four hours.

One more light buffing followed by a third coat of the sealer the following day and the job was done.

We are very happy with the results. It was important to us to preserve the original color of the wood. The Arboritec Avenue floor finish did just that. It didn’t darken or stain the floors, but added a very slight gloss.

That’s the reward for reuse and we love every bit of it! Just couldn’t get enough looking at those old but new floors. Well, soon they’ll be covered up again, in preparation for the wall painting.

Floor coating – cost fuzz

Sanding our old hardwood floors was the easy part. Particularly for me, as my job was just to watch and learn, to get stuff out the way and to manage the power cords.

Getting things set up for the floor coating was a lot more complicated. Mainly because it involved a lot of research.

Most common floor finished are polyurethane based and have a very high VOC (volatile organic compound) content. Something that was not acceptable to us, as we are very conscious about managing indoor air quality (IAQ). And like with paint, we were looking for a VOC free option.

Well, the first thing I learned is that there currently is no such thing as a zero-VOC floor coating. But there are water based products that have very low VOC levels.

The current LEED system, which can be used as a guideline, permits a VOC content up to 275 g/l (grams per liter) for floor sealers. Some water based products are at the 275 g/l threshold, others have a lower VOC content. A look at the specifications usually tells how the product performs on the VOC spectrum.

The next lesson was about the product costs. Your typical polyurethane/high VOC products run around $40 per gallon. The water based options ranged from $40 to $120 per gallon.

Needless to say that I immediately focused on products at the lower price range. That didn’t last long, for two reasons. First, the products reviews that I found were non-conclusive. Second, our flooring contractor, Frank, flat out refused to use any water based product that was not two component based, i.e. did not come with a catalyst.

All right – this will need some more dissecting:

Frank likes quality work and has a good business sense. He knows that using a economic product that has a limited performance span will eventually nip him in the butt. That explained his refusal.

What I learned is that the more economical water based products do not come with a catalyst (also referred to as hardener) and apparently wear off pretty rapidly. Only the higher priced options come with a catalyst, which is mixed into the sealer just prior to the application. These have the reputation to last a few years longer.

Still, the purchasing decision was anything but straightforward. Using the most economic two component water based product with the lowest VOC content would be the logical choice. Except that we ran into supply problems.

Water based floor coatings are not that commonly used, because of their price point. Retailers are hesitant to keep them stocked, because they have to purchase the product by the palette and then sit on it for several months, if not over a year, before it is all sold.

We had to investigate all the products that were locally available, and see which one was stocked at the quantity we needed. We finally settled on Arboritec Avenue, but had to source it across three different retailers to get the quantity we needed.

Here is a quick summary of the few products we investigated:

Arboritec Avenue
VOC content: max. 200 g/l
Coverage: 350 – 400 sf/gallon
Drying time: 1/2 – 1 hour

Bona Traffic
VOC content: max. 210 g/l
Coverage: 350 – 400 sf/gallon
Drying time: 2 – 3 hours

Bona Traffic HD
VOC content: 125 g/l
Coverage: 350 – 400 sf/gallon
Drying time: 2 – 3 hours

VOC content: max 250 g/l
Coverage: 550 – 700 sf/gallon
Drying time: 2 – 3 hours

Bathroom cement board

It’s time to put up some walls in the bathroom – which puts me squarely back on one of my favorite building topics: moisture management and indoor air quality (IAQ).

A bathroom, in building science terms, is considered a wet room. Splashes, drips and leaks are inevitable, and can over time lead to structural problems, but also IAQ issues such as mold with negative health impacts on the occupants.

This and any associated durability issues are easy to avoid by falling back onto a few simple moisture management strategies.

One of them is to employ floor drains. We documented the installation of the 1st and 2nd floor bathroom drains in a previous post, and there is more to come in one of the next posts.

Another strategy is to use cement board or fiber cement board as a wall cover in shower stalls, bathtub enclosures, and behind lavatories and toilets.

To give you an idea how water resistant cement board is… I had a leftover piece sitting in the yard for one and a half years, exposed to the elements. It was still in perfectly good shape and I ended up using it for one of our window sills in the basement.

Do not use green board or any other kind of paper-faced gypsum board product. These things are not suitable tile backer products and can turn into big mold traps.

See also Building Science Corporation, Info-306: Interior Water Management

What about the areas that don’t receive tiles, such as the ceiling and the upper half of the wall behind the lavatory and toilet?

Regular drywall will do the job, at the cost of around $6.00 per sheet. The green board products run twice as much (around $12.00 per sheet).

But what about the green board’s mold resistant property? Wouldn’t it prevent mold formation on the walls and in corners? Isn’t that worth the extra cost?

I would say no. Because if a bathroom requires such mold resistant product, there is an insulation/condensation and ventilation issue. And the extra $6.00 per sheet for green board won’t solve those problems, just prolong the denial about the real issues for a little longer.

Hot 4th of July

… not only in Chicago, but the whole Midwest.

Once it became clear that it would get steamy, I began to take records of daytime highs and nighttime lows based on the thermometer along the north side of our building. All readings are shade readings.

Tuesday, 07/03

  • High 98F (37C)
  • Low 79F (26C)

Wednesday, 07/04

  • High 104F (40C)
  • Low 82F (28C)

Thursday, 07/05

  • High 107F (42C)
  • Low 83F (28C)

Friday, 07/06

  • High 106F (41C)
  • Low 84F (29C)

Saturday, 07/07

  • High 98F (37C)
  • Low 75F (24C)

Cathy took the dog for a walk on Saturday at 9:00 am, when we were close to the high of 98F. She wished she would have waited a couple of hours, because by 11:00 am the wind shifted to the northeast and temperatures crashed. Before we knew it, we had a stiff, dry breeze with temperatures in the lower 80’s. Boy did that feel pleasant after three days of 100 degree temperatures!

How did we cope with the heat? We kept all the windows and doors shut, and hoped that our insulation would help keeping the inside comfortable and cool. To maintain good indoor air quality, we run the ERV for brief periods in the evening and again in the morning.

That worked pretty well, except that humidity levels rose to the point where it got uncomfortable. To manage summer humidity in the garden unit, we bought an efficient portable AC last year. It is a product by Whytner (Model: ARC-14S), with an Energy Efficiency Ratio (EER) of 11.2 and a specific dehumidification setting.

We turned it on for a couple of hours in the morning and again in the evening, while outside temperatures were somewhat cool. The total run time per day may have been up to five hours. The energy consumption of the AC per day ranged from 4 to 5 kWh (measured with a Kill a Watt (TM))

That allowed us to maintain the indoor temperature at and just below 80F (27C) with comfortable humidity levels. Also, the ceiling fan over the bed made for some very comfortable nights.

We had another excellent way to cool off – in the Park District pool just across the street (1/3 mile), barely five minutes’ walking distance.

This is where our initial research back from the house hunting days begins to pay off. The pool admits the general adult public from 6:00 to 7:00 pm, and it’s free! Cold pool water has never felt so good!

I had to figure out what kind of daytime work I should and could do on the 1st floor, which is not conditioned and got rather steamy. How about installing radiators?

More about this later…