Monthly Archives: March 2011

Drywall continued…

I like the drywall hanging, even on the ceiling, as long as I have a drywall lift. You put in a good day’s work and feel tired at the end. But you can look back and really see the dent you made.

For me it was time to take on the basement walls and make a dent there. Hanging the gypsum board on the walls didn’t involve a lot of heavy lifting because all of the sheets were cut down to fit to the framed wall portion.

The down side was that I had a lot of cutting and fitting to do. Unlike the ceiling, where the challenge was limited to fitting the drywall around the center columns, I had to work around all the windows, doors, wall lights and outlets on the walls. That did slow things down a little.

In a couple of places, the rockwool insulation bulged out from the wall framing which made the drywall hanging a little tricky. In those instances I needed help to keep the drywall pushed up against the framing while attaching it.

With the walls done, this garden unit really takes shape and begins to look like a living space. The best thing is that the space now got even lighter!


Drywall ceiling

Now that the resilient channels are installed there is little holding us back from putting up the drywall on the ceiling. Except that this kind of work has a bad reputation. Maybe it’s because few people like to lift and hold 5/8 inch Type X drywall sheets all day long.

Well, there is a solution called a drywall lift. I went to our local equipment rental place not far from where we live and was able to rent one for a reasonable price.

Once we figured out how the thing works, I very quickly began to love this piece of equipment. With the lift, one person could do the ceiling job, as long as that person is OK placing the sheets on the lift. If you asked me, it was worth the investment.

It gets even better. Not only did I have Cathy’s help but that of our friends Scott and Carlos. Together we were able to quickly make a real dent in our task list.

It is really interesting how the drywall begins to transform the space in the basement. This has been a very dark place for the past year we have been working down here. It got a little lighter since we put the insulation in. But the drywall got us to a whole new light level. I sort of have to get used to it.


Sound Solutions

Let’s step away from the bathroom and tiles. We still have some serious work in the living space that requires our attention. Let’s start with a look at the ceiling.

Our two insulation layers are in place, the open cell foam and the rock wool. Although these are insulation layers, insulating is not necessarily their primary purpose.

The three inches of open cell foam provide us with an airtight ceiling. Yes, this layer as well as the rock wool will slow down heat transfer, but the other function that we are really after is sound control between the first floor and basement.

Both products, the open cell foam and rock wool, have sound reducing properties. Reading through the product specs, I came across the term ‘Sound Transmission Class’ (STC).

I learned that STC measures the transmission of airborne sounds. I could not find any reference to the STC scale range, other than that the higher the STC, the greater the sound transmission reduction. The International Building Code of 2006 requires an STC of 50 between dwelling units.

The open cell foam, according to the product specs, should provide an STC of 37 in a 2 by 4 wall assembly. The rock wool offers an STC of 45 under the same conditions.

We don’t have either product in a 2 by 4 wall assembly, but rather in our ceiling, and I am not sure what their combined STC would be. What we did notice, though, was that we could no longer freely communicate through the ceiling.

“Even though a joist floor has a good IIC rating, footstep sound with a frequency of less than 100 Hz can still be annoying to the people below.”

Source: Controlling the Transmission of Impact Sound through Floors – National Research Council Canada

Yep! I can confirm that footsteps were still audible, because their sound originates through structure borne vibration, not airborne sound, and easily transmit through the floor joists. But what is that IIC rating thing? Well, structure borne vibration is not measured in STC but has its own metric called Impact Insulation Class (IIC).

“The higher the IIC, the better the attenuation of impact sound, with 50 usually considered the minimum rating for occupant satisfaction in residential buildings.”

Source: Controlling the Transmission of Impact Sound through Floors – National Research Council Canada

Even though I came across an interesting IIC ratings catalogue, I could not find a firm rating for our scenario.  I assume, through interpolation of the data, that we should be somewhere around IIC 50. However that would not take into account the three inches of open cell foam, but assume the use of a resilient channel.

resilient-channelThis is where I came across the resilient channel concept. It is basically a metal furring strip that allows us to decouple the drywall from the floor joists, and as such reduces the structure borne vibration transmission (i.e. the sound of footsteps).

We had to improvise a little to get the maximum decoupling effect. The use of a half inch insulation pad between the floor joist and channel and neoprene washer under the screw head should help with the reduction in vibration transmission from the joist to the channel. The closed cell foam tape at the bottom of the channel may further reduce transmission from the channel to the 5/8 inch drywall.

Boy, they were not kidding when they put the science into building science. How about leaving the brain behind and getting the brawn involved?

I don’t know what IIC rating our floor/ceiling assembly would yield. I assume that it will get us above the critical 50. And if we use runners on the first floor in the high traffic areas, we should be in great shape.

PS: Thanks to Drew for his help with the installation!


Finishing the bathroom tile

Cathy took on the grouting of the bathroom floor. We picked a grout that has a very similar color to the floor tile in the hope that it will hide any remaining irregularities in joint width.

It’s sort of obvious, but there are a lot of joints to grout with the small two inch tiles. That in turn requires extra attention to make sure that all joints are filled and packed with grout all the way. It doesn’t hurt to go back a couple of times and spread additional grout that may fill little nooks and crevices that one missed the first time round.

The last thing we want is to leave a little gateway for the water to get underneath the tile.

We let the grout dry and cure before moving on to the wall tile. The bigger 12 by 12 inch tiles make the installation pretty easy and speedy.

The disadvantage of the larger tile is that cutting around drains and water supply lines becomes cumbersome, but was still manageable. The cutting and fitting just slowed the process down quite a bit.

Looking at the finished wall tile installation, we opted for a darker grout color. While it was desirable to have grout and tile color similar on the floor, to mask the joint irregularities and take some of the busyness of the small tile away, we agreed that more distinct joints on the larger wall tile was preferred.

Based on my grouting experience in the laundry room, I proactively protected the floor from all the darker grout droppings. I knew that the grouting would be messy and was eager to prevent stains on the finished tile floor.

Despite my difficult start, we are very happy with the end result. We feel assured that we have done our due diligence with all the moisture management aspects, which should provide us with good long-term durability and indoor air quality (IAQ).

Finishing the bathroom floor and walls also got us a whole big step closer to actually moving in!


Trial first – to avoid the error

Those bathroom floor tiles instilled a lot of respect, and I would rather proceed very cautiously with the bathroom wall tile.

It would be nice if I could have a test run with some wall tile – like a mock up – where the result wouldn’t matter that much. It turns out that there is a good test location: the wall behind the utility sink and washing machine in the laundry room.

Here is anther little landfill diversion triumph: I had been able to get some leftover wall tile from another job, just enough for the laundry room project. This wall tile is different (smaller) than what we will use in the bathroom, but I still should be able to get a good handle on the installation process.

It turns out that square tiles are much easier to install than the hexagonal floor tile. I started a couple of rows up to make sure that the cut tile in this case is along the floor. The tile spacers are very handy indeed with the square wall tile and help to speed up the installation.

The other task that needed a test run, before moving on with the bathroom, was the grouting. I again used the laundry room as my trial location.

Grouting is a pretty messy job and requires quite a little bit of clean up. Like with the thinset mortar, the grout begins to cure pretty quickly in the bucket so it is a good idea to only mix small batches.

Compared to the bathroom floor, this was actually a positive experience. I now have the confidence to move back to the bathroom job.