Pads provide solid foundation for addition

Hey there, time traveller!
This article was published 01/09/2018 (2617 days ago), so information in it may no longer be current.

It was my assumption that additions to any house, including attached garages or even detached garages for that matter, would always require a concrete footing on which the framing would rest. I’ve since learned this is not always the case.

Pouring a concrete footing on top of six, 20-foot pilings to create the foundation below the main floor joists of my two-storey addition, as prescribed by my architectural drawings, was essentially the only support option that would satisfy the load requirements in my area.  The 32-inch crawl space created below the main floor framework was given a smooth slurry concrete floor, which can be accessed from the existing basement through a hatch should there ever be a need to address any issues that arise.  

Keith Yallits and Sheri Tharnovitch own a four-season cabin on a beautiful property nestled behind a plethora of foliage somewhere in cottage country near Grand Beach. After 21 years of enjoyment, the couple has decided to enhance their living experience by introducing a 30-foot-long by 10-foot-deep addition onto the north-side gable end of the structure. After a few initial discussions, Yallits met with Mel Clubb at McMunn and Yates to initiate the process with preliminary drawings. After a few modifications, and once the final drawings were approved and stamped by the engineer, the build was set to begin at the beginning of August.

Yallits and I have known each other for many years — I worked with him briefly as an engineering tech’s assistant for the City of Winnipeg in district 1 (back before the city amalgamated the districts). I have so many fond memories from that time, and it was a pleasure to hear from Keith.

Amidst sharing and reminiscing about the “old days” during our first official site visit, we did take a few moments to examine the job site’s topography and review the drawings in detail, as well as assess the tasks ahead. I had already ascertained that the addition would not require a concrete footing. The existing cottage had been built using posts and pads, and the ground is primarily made up of sand — “shores of old Lake Agassiz,” Yallits explained.

“The posts and pads of the existing cottage haven’t budged a bit,” he boasted.

I had my doubts, but we proceeded as the plans dictated.

The arrangement of the main floor support posts and pads, as well as main beam, ledger board and floor joists provided a sense of familiarity — it’s essentially like building the framework for a beefy deck… kind of a deck framework on steroids! Six-by-six posts are set onto 24-by-24-by-eight-inch pads at six-foot intervals over the 30-foot length. The main joists on 16-inch centres and ledger board are two-by-10, which sit atop a quadruple laminated two-by-eight level beam that rests on the six-by-six posts.

To support the exterior walls on either end, the two-by-10s are quadruple-laminated, and the joists below the main supporting wall for the split roof-line are quintuple-laminated. Once the main floor structure was fully constructed, ¾-inch plywood was glued and screwed to the joists to create the subfloor, on which the walls would be built.

Once the walls were in place, engineered trusses were hoisted into position for the lower four-12 pitch roofline on the backside of the addition, and 1¾-inch LVL beams were set 11 7/8 inches deep into position on the front side of the addition, providing a matching roofline with a five-12 pitch and a continuation of the vaulted ceiling throughout the front side of the cottage.

Once the roof and walls were sheeted with 7/16 OSB, I felt it prudent to check the level at various locations along the newly constructed structure. With all the weight generated by the addition’s framework, surely there would have been some movement. To my amazement, nothing had shifted in the slightest. The posts and pads set atop this ancient sand bed performed beautifully — my concerns were dashed in that instant.

We hope to have the addition completed by the end of October.

Thankfully, Yallits has been hands-on every step of the way, and it’s a big reason why the project is ahead of schedule. With the windows now installed and roofing set to commence, my focus will shift towards interior tasks.

And, because Yallits was correct in predicting nothing would budge, I swallowed my pride and admitted my concerns had been baseless regarding the stability of posts and pads atop a sand base. Oh well, rarely a day goes by without learning something. New knowledge is always welcomed.

So, let the learning continue… knowledge is power!

bossenterprise@outlook.com