A Roof[s] Over Our Heads

This house accused of having many corners… and many roofs. In total: five. Accuse away! I think it makes for exciting architecture!

Taos Pueblo - Talk about a lot of roofs!
Taos Pueblo – Talk about a lot of roofs!

We are almost done building the exterior walls, so this past week we focused on building the roofs.

Pile o'roofing material.
Pile o’roofing material.

We received the load of material from Randall’s (local lumber store) and it included: glu-lams, BCI’s, mono-trusses, dual slope trusses, parallams, and rim board, all of which are used to build different roof conditions. (I love that we can call one place tell them what we need and then they deliver it to the site. That is the benefit of working in a small town.)

We started with the guest suite roof. It is an independent flat roof, and therefore was the easiest to begin with. Here we used the dual slope truss, designed with an offset so that the peak of the pitch would line up with the bedroom wall. In reality, it probably doesn’t matter where the peak is because it can/could span the the whole length without supporting walls below.

Greg, Juan and Weasel lifting trusses into place.
Greg, Juan and Weasel lifting trusses into place.
Greg nailing them into place.
Greg nailing them into place.

Just like walls – after framing comes sheathing.

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While Greg, Juan and Weasel were working on the roof in the guest suite, Gil and Leaps started building the first rake wall in the master suite.

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Planning where to frame next is probably the biggest challenge for Gil. He is always having to plan ahead and figure out any complicated details so that his crew stays busy. And they move fast, so Gil has to move REALLY fast.

After the guys were done with the guest suite roof they all moved to the main living space.

Two Friday’s ago I was in LA so I missed the most exciting part of this roof, lifting the beams into place with a crane, but I came home to this:

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Beautimus Maximus

Above the beams we hung BCI’s to create a “hot roof”. Building code requires insulating your roof; in New Mexico we have to have R-38. The BCI’s over the beams creates a cavity in which to stuff batt insulation. Another option would have been to lay sheathing directly on top of the glulam beams and then 7 inches of rigid insulation on top of the sheathing to achieve R-38. See following diagrams.

Hot roof - option 1
Hot roof – option 1
Hot roof - option 2
Hot roof – option 2

I had specified using TJI’s in the roof plan, but what I didn’t know is that Randall’s only sources from Boise Cascade, another (the only other?) national manufactured joist supplier and therefore we could only get BCI’s.

TJI’s are sourced from Weyerhaeuser, which is the progeny of Truss Joist Macmillan, hence the ‘TJ’ in TJI (I stands for the joist shape.) BCI’s are sourced from Boise Cascade, hence the ‘BC’ in BCI. They are pretty much the exact same product.

The BCI’s are then hung by joist hangers, which are attached to rim board (extra thick plywood), which is attached to the walls. But, before we could slip the BCI’s into the joist hangers we had to add two pieces of plywood to the end of the joist webs, creating a ‘pack-out’. The flanges of the joist hangers would not have been able to nail into the web otherwise.

Beams, rim board, joist hangers, and joists.
Beams, rim board, joist hangers, and joists.
Roof framing from street.
Roof framing from street.

On either side of the glulam beams the guys also added a nailer strip, so that when drywall is installed there will be a surface to nail into. Eventually the ceiling will have drywall spanning between the glulam beams.

Adding nailer strip.
Adding nailer strip.

We also had to add fire blocking behind the rim boards. Again, fire-blocking prevents the fire from spreading from the walls up to the ceiling, or vise versa.

Leaps adding fire blocking.
Adding fire blocking.
Adding insulation because cavity will be covered by sheathing.
Adding insulation.

Last, but definitely not least, the guys started sheathing the roof. Oh boy, did that changed the way things looked!

Cuidado!
Cuidado!
Terminado!
Terminado!

While they guys were on the main room, Gil was back in the master suite, working on the cantilevered window. In order to build the wall that supports the high side of the pitch, Gil had to install the parallam beams over the corner window. Neither my dad, nor Gil had built a cantilevered corner window before, but they are old hands at carpentry, so they figured it out quickly.

We ended up using two, 3-1/2” x 11-7/8” parallam beams, connected perpendicularly by a Simpson LEG hanger. The hangers top flange rests on one beam, while the other beam rests in the hanger. The hanger is then bolted into the beam with lag bolts.

The first beam.
The first beam.
Hand for scale.
Hardware. Hand for scale.

The size of the hanger was a surprise to all parties, and it required some special cutting of both the beam and the sheathing, in order to make it fit.

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Plywood cutout to accommodate LEG hanger.

We also had to build a box out on the exterior side of the beam because the beam was only half the width of the wall and sheathing requires framing to nail into.

Looking out.
Looking out.

After installing the corner window beams, the rest of the framing over the master suite was easy: other rake wall, joists, and sheathing.

Closing up master suite.
Buttoning up the master suite.

Similar to the master bathroom window, we could not move on to the roof in the studio until we had the corner window beams installed.

First beam.
First beam.
Lifting second beam.
Lifting second beam.
More heavy lifting.
More heavy lifting.

This time around it was much more expeditious. Also, the roof above the beams is ‘flat’ (we used monoslope trusses) and a parapet wall.

In place.
In place.
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Corner window and parapet framing.

PLUMBING.

This week we also worked towards getting our plumbing ‘top-out’ inspection. To do so, all vents, clean-outs, p-traps, thermostat wires, exterior hose bibs, shower valves, etc., must be installed.

Plumbing is becoming less and less of a mystery to me. These photos help:

FHA straps.

The metal strip spanning the hot and cold water manifolds is also know as an FHA strap ( I have yet to figure out what FHA stands for), and it prevents sheet rockers from eventually puncturing plumbing.

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Foam placed around the pipe so that it will prevent ‘knocking’. If there is no foam, it sounds like someone knocking on the wall every time the water is turned off.

We also had to dig the trenches for the sewer clean-outs.  If there is a block in the pipe, the clean-outs access blockage.  There is a five foot maximum distance from the building, required by code.

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Brass caps.
Brass caps.

We went with brass caps in the courtyard, because of visibility.  They are nicer to look at.

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PVC caps.

PVC, functional and way less expensive, in the back of the house.

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Jose venting the fan in the bathroom.

My dad calls bathroom fans ‘fart fans’. They are not my favorite looking thing in a bathroom, but coming from someone who lives in a very small house, that little piece of audible privacy makes a world of difference.

FIREPLACE.

Harvey also returned to build the transition between the fire box and the metal pipe that will extend through the roof. He created a chase out of pumice brick, in which the pipe will reside.

That Harvey, he is so good.
That Harvey, he is so good.

We are painting the fireplace chimney matte black, per clients request.

Inspiration. Fireplace by Briggs Edward Simon.
Inspiration.
Fireplace by Briggs Edward Simon.

The tricky thing about painting a stainless steel surface is that there is a thin oil residue on it to prevent rusting, however it also prevents paint from adhering. We had to use muratic acid (smells terrible) to take off the oil, and then we were able to paint it.

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Harvey also built out the ‘banco’ (bench) on the side of the fireplace. It is a place to sit and look out the window and/or store firewood.

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All of the CMU block will eventually be covered in slate tile.

daltile

KEEPING THE SITE CLEAN.

Garbage. Every job site has it, every job site needs to dispose of it. Unfortunately construction produces a lot of waste material. We contacted Waste Management to inquire about renting a construction dumpster and it was $800.00 a month not including the dump fee. That wasn’t in the budget, so once a week, either myself, Ed, or Bruce (in any combination of pairs) makes a trip to the landfill. It costs about $38.00 to unload one ton of waste material. So, you can see that it did not make dollars and cents to hire Waste Management to do the dirty work for us. It is also kind of fun (and a workout) to unload the trailer.

Ed and Bruce sprucing up the trailer.  We got it from Oklahoma. Used trailers are surprisingly expensive.
Ed and Bruce sprucing up the trailer.

My dad is adamant about keeping the site clean, clean, clean. I don’t disagree. Type – A personalities.

Fast as Framing

I can’t remember the last job I had where I woke up excited to go to work. Since starting this project not a single morning has been sluggish. It is difficult to be indifferent when the project that you designed is manifesting right before your eyes. Akin to watching a favorite television show, it is a pleasure observing the carpenters frame up a wall and the masons lay the fireplace.

All it takes is one week of framing to turn a concrete pad into a semblance of home. Watching the entry wall go up was the highlight of last weeks ‘episode.’

Guys framing the entry wall.
Guys framing the entry wall.
Lifting the entry wall.
Guys lifting the entry wall.
Entry wall in place.
Entry wall in place.

The entry wall is over sixteen feet tall. Essentially a two story building, but instead of two floors it is a single floor with double height ceilings. An average sized person is one-third its height. This wall also establishes the height for the other pitched roofs over the master suite and carport. Its verticality and scale deliver a lot of drama to the courtyard.

Framing.

We have been framing for two weeks now, and are almost completely done building the walls. It is an incredibly fast process, so fast I can hardly keep up with documentation.

Ta-Da!
Ta-Da!

Framing begins by cutting the “bottom plates” to length for both interior and exterior walls. Bottom plates are made with pressure treated wood – lumber injected with a preservative to extend the life of the wood. Any lumber touching ground or concrete is exposed to water and susceptible to rot.

Bottom plates around perimeter.
Bottom plates around perimeter of slab.

Next, a layer of Sill Seal is laid under the bottom plate at perimeter walls. Sill seal is a thin blue foam gasket, which helps to prevent moisture from traveling up into the wood framing. The exterior bottom plates are then bolted to the foundation stem at all anchor bolt locations (remember when we poured the concrete into the CMU stem walls, and placed the anchor bolts every four feet?) At the interior wall locations both Sill Seal and anchor bolts are absent, instead a squeeze of liquid nails is administered with a caulking gun.

Sill Seal, or
Sill Seal, or “Sill Sill” as Greg likes to call it.
Gil squeezing out liquid nails.
Gil squeezing out liquid nails.

The interior bottom plates are then further secured with cut nails, thick and triangular in shape.  Cut nails are kind of “old school” according to my dad.  They are mostly just reinforcement until the liquid nails dries.

Pile of cut nails.
Pile of cut nails.
Cut nail at end of board. Secures bottom plate to foundation.
Cut nail at end of board. Secures bottom plate to foundation.

Note: there is some risk when hammering cut nails into the slab because they might puncture the radiant tubing – it has happened before, and is made evident by a loud hissing noise as the pressurized air escapes from the tubing. We fortunately got through this step unscathed. If we had punctured tubing, concrete would have to be ripped up and tubing repaired. The mark of a good builder (designer, plumber, etc.) is the ability to disguise a mistake, because they are bound to happen.

After fitting the bottom plates, the carpenters began to build vertically. This house is framed with 2×8 studs, 24” on center (o.c.) Typical stud spacing is either 16” or 24” o.c. because plywood is 48” wide and is nailed onto the evenly spaced studs. We decided to use 2×8 stud walls because visually I wanted thick(er) walls. (Thick walls are a traditional aesthetic in New Mexico – many old structures are built out of adobe brick, which makes for deep walls.) This also allowed for the windows to be recessed in the wall – not flush with the exterior surface. Recessing the windows required adding a 2×6 “pack-out,” around the windows, which provides material for the recessed window to be nailed into, and for the plaster (stucco) to wrap around.

Window pack-out detail.
Window pack-out detail.

There are two methods of framing a house. The first, and most preferable is to frame on the slab (a flat surface is required) and then lift up into place. The second method is what the guys call “stick framing,” which is literally building the wall in place, piece by piece. Some of the walls were too tall to build on the ground so we built them using the stick method.

Framing guest bedroom wall on the ground.
Framing guest bedroom wall on the ground.

I have drawn this handy dandy diagram to describe the terminology used while framing.

Typical wall framing diagram. Note: The horizontal “Bottom Cripple” is supposed to read “Bottom Plate.”
Typical wall framing diagram.
Note: The horizontal “Bottom Cripple” is supposed to read “Bottom Plate.”

There are a few rules of thumb employed in wood framed buildings. The first being, for openings greater than 5 feet, two trimmers are required on either side of the header. They help to support the long span. In modern design there are often openings greater than 5 feet and therefore many double trimmers.

Lifting the guest bedroom wall.
Lifting the guest bedroom wall.
View out of guest bedroom. Opening is way bigger than 5 feet!
View out of guest bedroom. Opening is way bigger than 5 feet!

Next is the California corner, made with three studs, and open to the inside. Typical wall corners are also made with three studs, however they are designated a “cold corner”, because once framed and sheathed (both done by the carpenters) it is impossible for the insulation sub contractor to go back and fill with insulation, therefore making it cold. Following is a diagram of both types of corners.

Corner framing comparisons. Plan view.
Corner framing comparisons. Plan view.

After everything is framed, or while the carpenters are waiting on a material delivery, they will begin sheathing the exterior of the building. That is a fancy term for covering it in half-inch plywood. The scale of the rooms drastically change between these phases; although the framing gives you a sense of the walls, the plywood really makes it feel like a room.

Sheathing the studio wall.
Sheathing the studio wall.
Shims between the foam and bottom plate help to hold the plywood in place while being nailed.
Shims between the foam and bottom plate help to hold the plywood in place while being nailed.

Tricks of the Trade.

A Story Pole is a long piece of wood, as long as the building is tall, with marks and measurements at every important element in the wall assembly: bottom plate, top plate, trimmer, beam, joist, roof, etc. It establishes the building height before it is built – an important visualization for any carpenter. It also provides measurements for the carpenters to cut lengths for the wood that will be used in the wall. Gil was adamant that we use a story pole because of the complexity of the roof lines in this project – it has proven its worth.

Ed and Gil discussing measurements while the story pole is on the ground.
Ed and Gil discussing measurements while the story pole is on the ground.
Vertical story pole.
Vertical story pole.

Gil is chalk full of carpenters tricks. For the upper part of the shed walls he snapped chalk lines on the ground to lay out the roof angle and the studs. These cuts can be very tricky and no two are the same. It is fool proof to make the layout on the ground first. Measure twice, cut once.

Framing the rake wall on the ground using chalk lines.
Framing the rake wall on the ground using chalk lines.

It is an odd sight seeing (hearing?) the carpenters work together – they have been doing it for so long that they hardly need to talk to each other. Their roles are as follows: Gil reads the plans and tells the guys what lengths to cut and where to begin; always working a few steps ahead of everyone, so that they never run out of things to do. Greg then follows, cutting and annotating the bottom and top plates. The annotation system that Greg scribes on the top and bottom plates tells Juan how to build the wall, which he builds on the slab. Meanwhile Weasel and Leaps are cutting studs and making headers for all openings in the walls. Once a wall is done, all the guys help lift it into place, stabilize, and make square. They work like a well oiled machine.

Labels on top plate. x= stud t = trimmer c = cripple beam = beam
Labels on top plate.
x= stud
t = trimmer
c = cripple
beam = beam
Writing on water bottles is another way they communicate - apparently weasel steals water bottles.
Writing on water bottles is another way they communicate – apparently weasel steals water bottles.

Rumford Fireplace.

In England, circa 1796, Count Rumford designed a tall and shallow fireplace with a streamlined throat that efficiently removed smoke and simultaneously prevented heat loss. We decided to use the Rumford fireplace design because the client wanted an open flame as well as an effective heat source. Typically, in Northern New Mexico, you see kiva fireplaces or stoves.  So we definitely are stepping out of the box with this one. If you are at all interested in learning more about the Rumford fireplace www.rumford.com is an incredibly useful website.

During framing we had Harvey and Gato (the same guys who built the foundation stem wall) build the fireplace. Once again they did a great job, and once again they made it look easy. To jazz things up we did a herringbone pattern on the firebox walls, and instead of running it vertically we turned it sideways. There are not a ton of firebrick color options, especially available in Taos, so I was bummed by the color of the brick, but it is growing on me.

Gato making sure Harvey is cutting a straight line.
Gato making sure Harvey is cutting a straight line.
Harvey laying the first brick.
Harvey laying the first brick.
Up close herringbone pattern for the firebox.
Up close herringbone pattern for the firebox.
Setting the throat on the fireplace.
Setting the throat on the fireplace.
Harvey adding another layer of CMU, to bring the hearth up to code - 18
Harvey adding another layer of CMU, to bring the hearth up to code – 18″ deep.

We are moving sooooooo fast – I need to start writing the next installment.  As of today we have the beams up in the main room and are adding the joists above.  It is a sight to see… in a few days.

Going Vertical

We did it! We made it out of the ground! Last week felt like my birthday – full of presents and extremely rewarding. Not only did we pour the slab, but we also built our first two walls. Let the vertical [games] begin!

However, before I get carried away let me back up and start with the slab.

I recently had a meeting with a client who wanted to connect his studio and main house to make room for his expanding family. While listing his desires (efficiency and affordability being paramount) he nonchalantly described pouring the slab as: “paving” the dirt between the two structures.

I wish it were that easy. (It has taken us a month just to get out of the ground!)

I guess I feel the need to drive this one home: concrete cannot simply be poured on the ground. No site on earth is perfectly level, and you need a level pad on which to build. (Have you ever lived in a house with sloping floors? I have, it causes vertigo.) It is also much easier to order the correct amount of concrete for a level building pad. A guessing game ensues with uneven ground; too much concrete and you can’t get your money back, too little and you’re screwed. It’s best to be level and right on the money.

Level building pad diagram.
Level building pad diagram.

In case you (or the aforementioned client) were wondering why the slab is so important, following is a list of its virtues:

-Transfers building loads to the ground.

-Anchors a building against lateral forces, such as wind.

-Isolates the building from frost and soil expansion (moisture).

-Raises the building above ground, providing a dry comfortable living space.

-Slows down heat loss from conditioned space.

-Houses plumbing and electrical systems.

-Provides a square and level substructure for framing.

Floor Systems

Slab-on-grade is literally just that. There are other floor system options, like crawl spaces, but slab-on-grade is the primary method used in New Mexico. It requires both plumbing and electrical trades do their rough-in before the slab is poured, whereas a crawl space allows for less precision in the rough-in – pipes and conduit are in the crawl space cavity and can be easily changed (not buried in 4” of concrete.) Crawl spaces seem preferable, but they are not compatible with concrete slabs.

Placing the Mud

The first step in “placing the mud” (a.k.a. pouring the slab) requires setting the height of the screed stakes and pipes. The pipes rest on the stakes and provide a guide for the screed (2×6 lumber), which levels the surface of the slab once poured.

Screed estaca.
Screed estaca.
Juan and Leaps setting the stake height.
Juan and Leaps setting the stake height. Pipe lying on ground.

Next, the layer of crusher fines below the slab must also be hydrated, so that it does not wick water away too quickly from the slab, which can cause cracking. Fortunately it rained overnight, so we didn’t have to wet the ground before pouring the slab.

Before pouring it is necessary to specify the “slump” of concrete mixture, which determines the amount of water added, and therefore the workability and how fast the concrete will set. I still don’t fully understand the water to concrete ratio – it depends on the mix (additives, type of cement, etc.) However, the actual method of measuring slump is pretty straightforward.

We specified a slump 5.
We specified a slump 5.

We poured the slabs over two days, and did so because we had five different finished floor elevations throughout the house. Monday we started with the patio (-6” B.F.F. (below finished floor)) the studio (+2” A.F.F.) and the carport footer (-24” B.F.F.). Wednesday we poured the slab in the main house (+0” A.F.F.) and the concrete stem wall in the carport (+18” A.F.F.)

Monday and Wednesday treated us well, providing ideal weather conditions: slight humidity, no wind, and overcast skies, all of which helped to delay slab dehydration. We started work earlier on those days, 6:45am, to beat the noon heat. I am telling you, the concrete gods were on our side last week.

It is imperative while pouring that the concrete crew rolls deep and moves fast. The concrete is coming out of the hose at 140 cubic yards per hour… FAST. Everyone is needed to push and pull concrete to far reaching corners.

All the guys moving fast and working hard!
All the guys moving fast and working hard!
Pouring our way into the main living space.
Pouring our way into the main living space.

Formwork

On Tuesday Gil and the guys built the formwork for the carport stem wall. I wanted a smooth surface on the bench and stem wall, so we lined the formwork with 1/8” Masonite. I also wanted the bench and stem wall to have a beveled edge in order to minimize concrete chipping, and increase comfort while seated. We ripped ¾” triangular wood strips and nailed them to the top of the wood forms – later to be removed with the formwork – and Voila! Bevel.

Before pouring the concrete in the forms, it is important to grease the formwork, making it is easier to remove them. We used a petroleum-based oil, in a spray can, and gave everything a good coating.

Ed greasing the formwork.
Ed greasing the formwork.
Pouring the carport bench and stem wall.
Pouring the carport bench and stem wall.

After we poured the concrete in the carport formwork, we then used a Sawzall, without the blade (a little trick the locals use instead of renting a concrete vibrator), to vibrate aggregate away from the walls, enhancing both the smooth and uniform concrete finish.

Vibrating the formwork with a blade-less Sawzall.
Vibrating the formwork with a blade-less Sawzall.

To jazz things up, we cut out the year MMXV (2015) in wood and glued it to the Masonite, creating a bas-relief in the bench. That way, in 10,000 years, when archeologists are digging up this ancient site, it will have a time stamp. Move over Pompeii!

Roman Numerals.
Roman Numerals.

Finishing

Finishing began immediately after the concrete was laid. The first step in finishing is screeding, which creates a relatively level surface.

Gil and Greg screeding.
Gil and Greg screeding.

There were still uneven areas in the slab, which the bull float eventually leveled out. Martin, the owner of Maes Electric, is the supreme bull float operator. I don’t think there is anything he can’t do (he does earthwork, electrical, and concrete). I asked him if he could do plumbing, and he said “No, the only thing I knows is that shit runs down hill!” (He must have heard that joke from my dad.) I have a feeling he was being modest. In fact, he doesn’t normally work with Gil and the guys, but he is so good at the bull float we brought him on for the day.

Martin riding the Bull.
Martin riding the Bull.

Next, we hand troweled, smoothing out the surface with metal concrete trowels. In order to get to the middle of the slab, the guys had to kneel on kneeboards.

Hand-troweling on kneeboards.
Hand-troweling on kneeboards.

The last step in finishing is the power trowel, which Martin was also the master of. The metal blades on the power trowel must be adjusted to the perfect angle, or you will gouge out chunks of slab – it requires skill.

Martin pushing the power-trowel.
Martin pushing the power-trowel.

We ended up with three concrete finishes throughout the house. The patio received a broom finish, which is good for traction when left exposed, or as a substrate for further finishes – tile or stone. The studio has a smooth hand troweled finish because it will remain exposed. The rest of the house was finished with the power trowel; it will eventually have wood flooring covering it.

Done.
Finished.

Curing.

It takes 28 days for concrete to completely cure, but within an hour it is walkable. After the concrete slab was finished, we put down a layer of 6mil Poly – opaque plastic sheets, 20’ wide x 100’ long. We weighed it down with CMU block and extra rebar, and then doused it with water from the hose. The poly remains for as long as possible to protect the slab from the elements.

Curing the slab.
Curing the slab.

After the concrete cured overnight we cut control lines with a skill saw, ¼” deep, at locations throughout the house that were most susceptible to cracking.

Ed and Bruce cutting the control joint.
Ed and Bruce cutting the control joint.

Masonry and Framing

We took Friday the 3rd off for the holiday, which was disappointing (only fore me). By Thursday the CMU wall for the fireplace was laid and the first wall was raised. I wanted to keep going!

Harvey and Gato, taking a break.
Harvey and Gato, taking a break.
The first wall up - fireplace wall in background.
The first wall up – fireplace wall in background.

This week will consist of framing, framing, framing!