Modern Residential Framing

Despite the fact that I work like a dog, I am incredibly lazy. I went back through my notes and realized that I haven’t provided an update on the KHouse Modern since the curiously popular Pier and Beam Foundation post on June 12th.

What is wrong with me?

KHouse Modern finished grade beams

The picture above is where we last left things, concrete grade beams were poured, forms were taken down and you could finally start to get a feel for house the house was laid out … if you are an architect. To most people it just looks like a bunch of concrete rectangles, but looks can be deceiving. Considering I know just how much work went into getting to this point, I am always amazed at how simple every appears. However, getting something wrong at this stage means everything after will be wrong. All the embed plates, drop heights, brick ledges, inverted brick ledges, joist pockets, etc. have to be coordinated and resolved. It looks simple because that’s the point.

pouring the floating concrete slab in the garage

Technically there will be four major concrete pours on this project – as of this writing, we have done two. The last two will be the lower level garage and the site flatwork (sidewalks, retaining walls, etc.). This is the upper level garage just prior to concrete pour #2. This is technically a “floating” slab because the slab floor isn’t poured integrally with the grade beam walls. There will still be very little movement on this slab because we followed the same procedures as the grade beams themselves. The slab is poured on top of void cartons so there will be an air gap between the soil and the bottom of the slab.

Confused? Read the Pier and Beams post – there’s a link at the beginning of this post.

the concrete slab between the house and the garage

Another look at the upper level garage and the remaining concrete slab work that we poured. You can see the garage slab on the right, the walkway between the garage and the main house in the narrow band in the middle, and then over on the left-hand side is a tornado room (which is why it has a concrete floor within the footprint of the main house.)

setting steel posts in residential construction

So today’s post covers about 8 weeks of construction work – which at this stage of the work covers a lot. There is quite a bit of steel in this house – it’s to accommodate the uninterrupted spans that we have as well as the walls that are entirely made up of floor to ceiling glass. Around the perimeter of the house, we have 6″ steel columns that run in parallel with the glass windows walls (take a look here) Did you know that it takes 5 people to raise and weld a 6″ steel column to the steel embed plate cast into the concrete grade beam?

I didn’t either.

steel posts are in place

This picture was taken just a few days after the previous photo – we went from just a handful of steel columns to almost all of them erected in place along with all the floor framing joists. I don’t have the ability to go by the project site more than once or twice a week so there are times when it definitely feels like I’ve missed something.

floor framing using TJI's

We have a fairly sizable crawl space on this project – 52″ to be exact. Part of this is due to the site sloping downhill from the point of entry to the rear alley. Another reason is that we wanted the approach to the house to be elevated so that there is the experience of entering up into the house rather than descending down into the house. The combination of the two allowed up to created this heightened space under the floor to locate most of our HVAC equipment. [for those who don't know, HVAC stands for Heating Ventilation and  Air Conditioning] 

You can see in the picture above where the floor joists have been modified to allow for air conditioning vents that are supplying air through the floor.

a floor system explained by Bob Borson

In the above photo, I have jumped down into the crawl space to document a few things. I have tried to label most of the items in this picture, it’s a pretty clean space [other than a piece of concrete masonry block - which I can assure you is now removed]. There is a steel beam in the picture above that has a piece of wood covering it – I’ve labeled it as “Not Structural”. It wasn’t in the details so I asked the contractor about it – it didn’t seem to serve any practical purposes. The contractor told me that it was installed on the beam to protect it during transport and the just decided to leave it on.

Installing the HVAC equipment

The air conditioning work continues with the installation of the ductwork and the floor registers. This is not particularly pleasant work to do when it is 100° outside. Think these guys are thinking about the cold air that will be moving through these ducts as the work in the heat, all hunched over working in the crawl space … even a crawl space as nice as this one?

[shudder ... and not because I'm cold]

running ductwork under the floor joists

In case you were wondering, we specify rigid ducts on our projects rather than flexible duct. We allow a run not to exceed 4 feet to transition between rigid duct and the register but for the most part, the interior of the ducts are nice, smooth, and straight. This helps maximize the efficiency of the air distribution, but don’t get me wrong – flex duct when installed properly can work extremely well, it’s the “installed properly” part that’s tricky.

Framing for the Garage starts

I included this picture only to show that the framing for the garage had started on this particular site visit. At this point – literally – they had two walls partially framed. In the 30 minutes or so I spent on site, the framers made a LOT of progress:

Framing the Garage using TimberStrand

Of course, that’s pretty easy when you have 8 guys and the superintendent working on this one area. I asked the contractor about why there were so many framers working on this one area and it’s because they were there to install the decking on the floor of the main house but had to wait on the city inspector to show up (he was running late). Rather than have a bunch of guys sitting around doing nothing, they framed this garage in no time at all.

KHouse Modern Patio Section

I mentioned earlier that there is a lot of steel on this project – it’s what’s helping us get the cantilevers, window walls, and open spaces we want. This required not only steel posts, but specialty steel brackets to work with our wood framing. I have included a wall section through one portion of the project that highlights the cantilevers and window walls on this project. You can click on the drawing and it will open up in a new window at a much larger size. [I should also note that we are making progress with our graphic standards

Here is a close up look at some of the steel brackets we are using as well as a few photos to show where and how they are used:

custom metal brackets - secret construction techniques

wood beams supported by steel post

wood beams supported by steel post

steel knife plate for wood framing connection

The use of steel and framing techniques like these really goes a long way into creating the drama that people frequently associate with modern residential design. The steel allows us to isolate the structure from the walls which in turn allows us to open those walls up as much as we want to – and if you don’t know (or simply can’t remember), here is the starter kit of classic rules for modern architecture:

• adoption of the machine aesthetic
• materials and functional requirements determine the final product
• emphasis of horizontal lines
• express the structure of the building
• rejection of ornamentation – the simplification of form + elimination of “unnecessary detail”

Steel goes a long way into allowing us to accomplish almost all of these rules … not that I follow the rules.

a big cantilever

There there you have it, modern residential framing and an update on the last 83 days of construction  - sort of. I tried to catch you up but even then, I haven’t shown any photos beyond Aug 26th.

We now have the roof framed.


Bob AIA signature