A Tale of Three I-Beams

The first floor of our home has a 19' wide by 6 ' deep balcony off the den and laundry/mudroom. Originally planned to have pilings supporting it, the city was concerned about controlling drainage that far down the slope and the excavator was concerned about how to move equipment down there. So instead of pilings for support, we are cantilevering both the first and second floor large decks. Honestly, it's a much more pleasing design. It's also a lot more steel, problem solving and more headaches for our builder, Brian. That's okay, he can take it!

On Monday, August 14th my brother came out from Ridgefield to watch the fun. Honestly I thought it would take longer than it did to place three very large I-beams, one on the east foundation wall, the center one resting on the north foundation wall and the big wood beam in the center of the house, and the third one resting on a sort of foundation pony wall perpendicular to the north foundation wall and running half way towards the front of the house. This last beam also rests on the big wood beam.

Placing the beams is precarious enough with out having to joist walk at the same time. These guys took it in stride. Did I mention that each of the beams was different? Two have fins welded to the bottom with bolt holes so the beams could be secured to the foundation, but the fins were different sizes. All three beams have bolts sticking up from the top, part of the hold downs to secure the house to the foundation, but they were all in different locations. The beams also all had flanges at the north end, specifically designed to hold large wood beams that would be the north edge of the deck. 

All three beams place, it was time for some fine-tuning using the the all purpose fine-tuner. The sledge hammer.

All three beams placed, no one injured, I could exhale. For a while anyway, because in two weeks the crew will deliver three more I-beams to be installed on the second floor.

Holding Up a House

Pilings, check. Grade beams and foundation, check. Drainage managed, check. City happy? Check! Now to get started! Sill plates were installed on the foundation walls and secured using the threaded rod encased in the concrete. A series of wood beams - 8x12 inches were installed across the breadth of the house and secured to the east foundation wall and the garage foundation wall on the west. These beams are holding up the house (they have a lot of help).

Floor joists were installed and space left for three steel I-beams for the cantilevered deck outside Scott's den/second bedroom. Our future elevator shaft was delineated (with elevator pad below and removable floors if and when we need it) and the bump out on the back of the house that extends the stair landing out to six feet is evident!

Future elevator shaft

Stairwell bump out

Drains, Conduit, Gravel and Extended View

 

Once you have a foundation you build a house, right? Well, not according to the architect, engineers, builder and the City. First you have to install drainage. And a lot of it if you are building on a slope like we are. In fact, managing water, from around the foundation and off the decks was a major concern for the City. It's a part of the reason we have cantilevered decks instead of posts and why the permitting process took so long.

The foundation in place. Neal, the excavator guy, came back and after backfilling some around the grade beams, installed drain pipe all along the foundation of the house - amazingly called "foundation drains". The foundation drains all run to a sump pump installed in the crawl space, which then pumps any water collected from the foundation drains and the garage drain out to the street. While we waited for the City inspector to approve the drains Neal backfilled the garage with gravel up to the entrance point for the conduit from our future heat pump. 

The conduit installed across the gravel and into the crawlspace, Neal proceeded to fill the garage with more gravel to about four inches from the top of the foundation. 

Scott with Neal, the excavator guy

Now this likely sounds fairly mundane to you, our reader, but to us it was something we had been awaiting for almost seven years. What was our view from the back of the house? It didn't disappoint!

The City inspector approved the drains and Neal got back to work. First laying landscape fabric over the foundation drains, he then maneuvered his excavator to backfill gravel around the foundation.

Laying a Foundation

When last we checked in on 464 Astoria View we had grade beams. Grade beams are the foundation for the foundation and will keep the house from sliding down the hill, Rule #1. Next up, forms for the foundation! Pictured above, you see the exterior forms for the back and east side foundations (Scott for scale). The back foundation is quite tall because the slope of the lot starts about halfway through the house, and when they were excavating they had to carve down further than planned due to soil conditions.

Garage foundation forms and rebar

East side foundation forms and rebar

Foundation forms and rebar for the rest of the house 

It took about a week in all to get the foundation ready - putting up the exterior forms, do the rebar, the City inspection and interior forms - then the big day!

Using another large concrete pump and two more trucks of concrete, Alex and his team poured our foundation on July 25th, 2023. Not without mishaps, an interior form blew while they were pouring concrete in and made quite the mess. Not deterred in the least, Alex and team jumped in, fixed the form and cleaned up spilled concrete. Not their first rodeo. The next day the forms were removed and our newly poured foundation revealed!

Notice the threaded stainless steel rode sticking up from the foundation. These are
tied into the grade beams and, secured to the sill plate, will make sure
the house doesn't come off the foundation.

Garage foundation

Back wall foundation. Notice the grade beams under the foundation.

From Blank Slate to Design Development

In the fall of 2019 I was madly digesting everything I could about architecture and trends. The goal? Trying to figure out what kind of home we would build on the lot. Should it be modern? It would certainly stand out in the very traditional neighborhood. Craftsman? Lots of those in Astoria. Cape Cod with lots of gorgeous heavy woodwork? That one got a resounding "No". We started thinking about what we wanted - simple, easy, timeless. Not overdone. I hit Houzz.com, looking through interior and exterior photos, showing select ones to Scott (who did not enjoy this process near as much as I did). We eventually settled on modern with a Scandinavian influence. 

Mangosteen House, designed by Chadbourne+Doss

I started following architectural firms on Houzz that were in the Pacific Northwest and skewed modern. There are a lot of good ones in Seattle and Portland. And I quickly found that almost all of them had a minimum contract well over our budget. One of the firms, Chadbourne+Doss, responded that they work on both big and small projects and were intrigued by our lot and the prospect of building modern in the small traditional neighborhood. And in addition to their main offices in Seattle, they had a location in Astoria. Their project photos on Houzz were very enticing.

We met Daren Doss at the lot on the day of the core drilling in March of 2020. It was cold and blustery, normal for Astoria, and we talked about our requirements and vision for the house. Daren thought it could be done and we decided to follow up in the next week with a full conversation and next steps. We drafted our basic requirements as follows:

1. House must not slide down the hill
2. See rule #1
3. Do not skimp on external (envelope) materials 
4. Do not over-build for the neighborhood
5. Age-in-place (elevator is an option)
6. Clean, well-edited design (think Scandinavian modern-ish)
7. Green building and energy where practical - leading, not bleeding, edge
8. Quality, not quantity - no underused space 
9. Focus on views on each level
10. Smaller private spaces, larger public spaces
11. Master with private balcony
12. Large main floor balcony 
13. Lower level recreation/bunk room

We were assigned homework. A list of questions like, "If your house were a car, what kind and why?" to which we answered: A Mini Cooper S because it's fun, yet practical; sporty and fuel efficient; bigger on the inside than it is on the outside. There were a lot of questions about movies and music, what our days look like, our routines. How we wanted to live in and out of the house. It was fun and made us think about what we really wanted.

    

The results of that work, along with the preliminary geotechnical report and the survey, were three design options presented in February 2021. The exterior elevations and interior floor plans varied widely. I liked the Option 1 exterior, but the floor plan wasn't going to work for aging in place. Option 2 had a first floor kitchen and living area we liked, but the second floor was chopped up and the exterior elevation didn't do it for us. We selected Option 3 because it was the only one that included an elevator, we liked the flat roof design, and the floor plan, while still needing work, was closer to what we had in mind.

The Design Development phase included two major iterations in May and July 2021. The biggest surprise was the flat roof - it disappeared. This was a disappointment because we really liked the look, but the roof was just too big to do it well. And we wouldn't be able to take advantage of solar energy in a big way, which is something we really want to do, so shed roof. Other changes between iterations were exterior materials and kitchen window height, the addition of a powder room and butler's pantry, firewood storage and a three foot bump out at the stair landing that changed the back elevation in a positive way.

That's a Lot of Steel

 

The month of July was a very busy month for us and for the contractors building our home. Scott and I had been "moving by Mini," making many round trip runs to Astoria with the boot packed to the roof with items that weren't going into storage. The advantage of these day runs was that we were able to stop by the house and see the progress! On one such run, I think on a Saturday, we were greeted by the scene above... forms for the grade beams!

The following week Alex and his crew - mostly his sons aged ten or eleven years to early twenties, and some old hands - placed the rebar in the forms. From a layman point of view it seems that the core physical difference between grade beams and foundations is the size and sheer amount of rebar contained within them. (I know, they do different things...)

One of the pilings, at the center of the foundation, had been driven in about a foot from its intended location, but still within the boundary of the grade beam. In order accommodate the misplacement and ensure the strength of the grade beam, even more rebar was employed near the misplaced piling. You can see the extra rebar down the center of the photo above.

Cement was poured using a very large cement pump. We're told that the grade beams used three cement mixer trucks worth of concrete. There is a lot of rebar coming out of the grade beams which will tie the foundation to the grade beams. 

In addition, there are quite a few stainless steel threaded rods ranging in length from 3 feet to 12 feet depending on their placement along the foundation walls. These rods are tied into the grade beams and will go through the foundation and become hold downs for the framing. I don't think this place is going anywhere!

What's a Grade Beam?

It didn't seem right. All those pilings pounded into the ground and all we have to show for it is about six inches of pipe and a cap. Well, twenty of them. 

Not being an architect or engineer, I have very little knowledge of what goes into building a house. When the architect said we would have to build the house on pilings I imagined the house up on stilts like you see at the beach on the east coast. (My grandfather, a home builder his entire life, would be aghast.) Our architect quickly disabused me of that notion, explaining that the pilings would been in the ground and that grade beams would connect them to create a very sturdy platform on which to build our house. Cool. what's a grade beam? Off to the internet for answers. 

Grade beams serve two purposes: it acts as a beam that carries the foundation load while simultaneously bracing the foundation. Unlike a spread footing, which primarily supports the foundation via latitudinal reinforcement, grade beams utilize longitudinal reinforcement for the bulk of its weight-supporting bearing. The beams essentially act as connectors between footings and pile caps. (Thank you www.alignfoundationrepair.com for a definition a layman can almost understand.)

Based on that description, spread footings distribute the weight of the foundation and building horizontally across the ground, while grade beams connect the pilings and spread the weight vertically down the pilings as well as horizontally. Got it, I think. So here's the plan:

Foundation walls are gray, piling locations are the little circles and
the grade beams are white with a black outline.

Rule # 1

 

Over three years ago, on a rainy, chilly morning in March 2020 large machinery set up under the tree to drill for core samples on our lot. Greeted by a sign bidding neighbors to "say goodbye to this tree/view" it didn't feel terribly welcoming. But, change is hard and folks don't like it. 

When Scott and I approached the geotechnical engineering firm the first thing we told them was "Rule #1. The house can't slide down the hill." Rule #2? See rule number one. After initial geotechnical review we were told that we could likely get by with a standard foundation - Yay!! Standard foundations are much less expensive than more complicated ones. Further reviews and a change of ownership of the geotechnical firm resulted in the bad news. Yes, the lot is buildable, but you will need a much more robust foundation which includes pilings and grade beams and it will cost significantly more. Sigh. But rule #1, the house can't slide down the hill.

So here we are three years later annoying the neighbors once again. Actually, the neighbors have been really great for the most part and Scott has done his level best to be a good neighbor. But it's easy to understand how disruptive new construction can be, especially when the new constructions requires pilings. Twenty of them. 

Starting in the northeast corner of the foundation, Pile King (yes, it's really the name of the company) pounded a 21 foot piling into the earth with a 3,000 pound weight. With the aid of a coupling they added another 21 foot piling, and another... In total the northeast most piling was driven in 45 1/2 feet! Fortunately that corner of the lot was the softest ground and most of the pilings didn't need to be driven near as far down. 

Compelling video...right? And just a bit noisy. You can empathize with our future neighbors! Over two and a half days twenty pilings were driven into the earth. Still, the plans called for 546 feet of 6 inch diameter pilings with 1/2 inch walls. Due to soil conditions a total of 811 feet of pilings were driven into the ground. The pilings were load tested to ensure they could handle the weight of the structure to be built on them. We were told we could build a skyscraper on them. I guess that checks off rule #1!