Framing the sunroom - part 1.

The first major goal for the spring of 2012 was to frame the attached sunroom on the south wall of the house. There are a number of factors that led me to build the sunroom in the way that I have decided to proceed. This first part of a new series on the sunroom will set the stage by covering some of the important design considerations.

The attached sunroom in an early stage of construction during the spring. Spring was early this year so I had plenty of time to get'er done before we were due to leave on a trip to the west coast at the end of May.

"Wing" insulation, drainage and parging.

With the foundation insulation done, it was time to turn my attention to insulating the ground around the foundation. This insulation for the ground is sometimes called "wing" insulation and is an important part of the FPSF foundation design. The wing insulation effectively protects the shallow footings from frost heave by raising the frost line towards the surface. In my case the insulation plan called for R20 insulation extending outwards 4' from the footings but 6' at all corners (except where the footings were more than 6' below final grade).

The colder the climate, the higher the R value the wing insulation must provide to keep the earth below from freezing. Also, the colder the climate, the further the wing insulation must extend outwards from the foundation. When the underside of the slab and footings are insulated as well, the R value of the wing insulation must be increased more still since reduced heat loss from the underside of the foundation will contribute less towards keeping the earth under the footings from freezing.

Waterproofing and insulating the rest of the foundation.

I was very excited to be done with the concrete work - it was  a big job and I was really looking forward to setting my own pace with the rest of the project. Before I could do that, however, there was one last reason to bring out a couple of the concrete guys again - the "Blueskin". Applying the "Blueskin" waterproofing membrane wasn't terribly difficult, but I wouldn't want to try it single handed - it's too sticky, awkward and expensive.

4" rigid foam around the exterior wall makes a good capillary break but something more is required to fight hydrostatic pressure. We applied the "Blueskin" membrane only to within 12" of the top of the wall to save material - this stuff 'aint cheap. The black line around the top is a mastic "goo" that seals the edge of the membrane to the wall.

Last push - forming and pouring the concrete walls.

"Last push" is me tipping my hat to the effort that was required to keep everyone involved with this foundation project on task. After the slab had been poured, I didn't want a general sense of accomplishment to derail my timeline - my parting words to the contractor that day were something to the effect of "see you in a few days". And so, a few days later the concrete guys were back to deliver a stack of forms so that they could start in on forming the walls - I think they were all starting to look forward to the end of this project as much as I was since most of their other work was back in town.

Formwork and rebar work underway. It rained for the first time in a while that day. However, the guys didn't seem to have any trouble keeping their cigarettes going despite the rain.

Pouring the slab.

After much scurrying about in preparation, the day finally came when we poured the slab. This was the only job in which I was an observer only. After watching the process, I have come to the conclusion that pouring a large concrete slab is not a job that can be done either single handed or by a crew of amateurs. There is simply too much work to do all at the same time - placing the concrete, raking, screeding, trowelling...

Continuing with the theme of unusually hot weather last summer, by 9 or 10 am these guys were already being beaten down by the sun.

Pre-slab preparations - part 2.

I ended my last post about the foundation on the day that the rigid foam had been installed and the decision to omit the 10 mil poly was made. The following day was when the concrete guys were to come out and install the steel reinforcing for the slab, which proceeded as planned with no problems. For reinforcing, a 10 mm rebar grid was laid out on 12" centres and tied together. With hindsight, I know this is over-kill and if I were to do it again, I would have argued for lighter gauge reinforcing in my plans. My concrete contractor kept joking that if I ever needed any extra cash, I could open up my basement to do heavy-duty mechanic work since I would now be able to park a bulldozer or excavator on the slab. Live and learn.

Pre-slab preparations - part 1.

With this post, I am jumping back to where I left off with my post on pouring the footings.

The footings had just been poured, the plumbing was roughed in and now it was time to fill the void. For fill, I used more of the same gravel that we had used for the pad. The form work that was left up around the exterior perimeter of the footings prevented us from driving a skid-steer over top of them. Instead we used the excavator that we had on hand to reach over and drop the fill in one scoop at a time. We then shoveled, raked, leveled and packed until the tamper bounced off the surface. The finished height of the gravel was three inches below the top of the footings to account for the thickness of the sub-slab insulation.

In this photo, my nephew Parker and I are finishing the gravel between my new footings. Parker did a lot of raking while I ran the packer. It was hard work but we had it all done in less than a day owing to the help I received. Even my mom pitched in - I warned her that the gravel was very heavy and hard to move but she replied "Don't worry Lucas, I'm a gardener."

Mud sills over concrete walls.

In my last post I talked a little about the mud sill assembly that over-lies the concrete basement walls. The installation of this portion of the mud sill was pretty simple but I think it's important to mention again that it is very important to make sure that time is taken to measure out the adjacent stick framed walls carefully so that the second top plate trasitions properly.

Footings.

Using a simplified foundation plan I had made from the architect's plan, the concrete contractor and I marked out the outer edge of all the perimeter footings and the center-lines of the peninsula footings. Even with the slim steel pins we were using, it was difficult to drive them into the compacted gravel. A string line was stretched between the pins to outline the house's footprint.

Planning for the foundation.

Once the gravel pad was complete, I had some time to get ready for the foundation job. I had made arrangements and agreed upon a start time with a local concrete contractor months before - yet for a variety of reasons nothing really happened until almost a full month after the proposed start date. Once the concrete guys got going things moved along pretty well... they started work after the first week of July and were finished during the first week of August. I have always been pleased with the quality of the work they did but my blood pressure goes up still when I think back on the time that was wasted waiting around.