I thought I would try to deal with the issue of home building techniques by examining a home that I designed and built, the LaRoe Residence, paying particular attention to the how-to aspects and relate them to an accompanying slide show. Click here for slide show.
For additional information covering an overview of the house, its design and features, including a slide show with solstice and finish home pictures click here.
The first issue is locating the house on the lot. Here, in the Piedmont area of North Carolina, this often entails walking around in the woods a bit and if your lucky you get to do it in winter when the leaves are down and the bug population is at its lowest. In this case, we are dealing with a passive solar home so we had to make sure we were far enough back from the ridgeline to ensure we could get enough winter sun. The other factors were being able to see the creek in the bottom on the north side of the house from the deck in winter, an existing house to the west, and a location for the septic system to the east and a road/drive to the west. Although we are dealing with 3.5 acres the options for the possible house locations were quickly minimized.
Outlining the proposed site with surveyors tape is always a useful technique. Everyone involved can get a clear vision and at this point you can see any problems associated with this placement, such as large trees you might want to save, setback and property line issues and of course the surrounding views. Once the site is fixed I pull out my trusty transit, a Gurley 400 W that is still wonderfully accurate after twenty-five years of service, and get the elevations at the house and the land contours surrounding the house. The height of the foundation and any critical grade issues are then set with string lines at the house location. Again we assess for problems and we also now have a floor height that we can set a ladder up at and make sure we have the views we want. In the photos you can see how the homeowner, Margaret LaRoe, immediately set up two chairs at what is going to be the entry to her new home. Click here.
At this time it is a good idea to set up your benchmark, in this case the top of the foundation, in a couple of different locations for easy access and verifications.
I have found that there is no substitute for going home now and transferring all these elevations numbers to a drawing of the foundation - north, south, east and west, with current and finish grades. Click here for Grading Elevations.
You will now have a very clear picture of what is about to happen, cut and fill lines, drainage, and you can calculate the quantities of block, concrete, waterproofing and backfill if needed. This is also the information for a structural engineer to calculate the strength needed in your basement walls. For this job we used 12-inch cmu’s with ¾ inch rebar every 64 inches, grouted solid, for the walls.
Lot clearing is always a dramatic time, a lot of visual change happens pretty fast. What to do with the trees and associated debris is a challenge if you want to do what’s best for the environment. We where lucky on this job as there was an established community that was very interested in using the trees, some wanted firewood, others split the trees for fence rails, others took some for woodturning. The remaining debris, stumps and limbs where trucked to a site close by, covered and left to decay naturally.
Well, it is time to cut and fill. An accurate layout of the foundation area is the starting point. I use ½ inch rebar for a lot of applications, you can cut it to any length, is very strong and drives easily into the hardest earth. After locating the foundation line I chalk a line 2 feet outside of the foundation line for the excavators and install and spray paint rebar marking the top of the fill lines around the house. Properly done, after digging and filling, you should now have control of the drainage situation around the house and in the basement area. We excavate to the bottom of the footings and make sure we have positive drainage out of this area. Controlling the water and installing a good access road at this point is a must and the benefits cannot be overstated.
Formed footings are not the norm in this area but I use this technique probably 95% of the time. The more complicated the foundation the more valuable is this technique; it allows you an accuracy that is unavailable with machine dug footings and is pretty much impervious to rain delays. The last time I used traditional dug footings we had to pump them out three times due to rain, we then had to remove all of the existing rebar with attached j-hooks and clean out the dirt that had collapsed into the trenches, scrap the bottoms to hard earth and reinstall the rebar. This was a waste of time, money and energy. As you can see from the photos, click here, the formed footings are flat, very level, have almost no waste and make the masons very happy – no reaching down below grade to lay the first courses, no mud, easy wheel barrowing and walking.
I use traditional batter boards and string to do the layout. This allows you to locate all points at any time. We set the batter boards at block coursing, 8-inch increments, above the top of the footings. Once we have verified the strings are accurate with the plans and square we use a plumb bob to locate the corners and other points we need, such as point loads. We then drive short ½ inch rebar into the earth at the corners and anywhere else we need them until the top of the rebar is equal to the top of the footing. Now you have a point, the top of the rebar, that you can easily level off of. We use the existing string lines to measure off of and finalizing the top of the rebar with the transit. Now you are ready to set your form boards. On this job we are using 2 x 10’s, secured with heavy-duty garden stakes that have been cut to length. We screw through the garden stakes into the 2 x 10’s once we have established the top of the footing. This system is pretty flexible as you can always remove the screws and adjust the height, as needed, large wooden wedges are helpful for this adjustment. After a final check we install black plastic wrap on the inside of the forms, virtually eliminating honeycombing of the concrete and allowing use to reuse the 2 x 10’s later.
With the increased availability of concrete pumps there is no reason not to use them, they save a lot of time and waste, not to mention the back breaking labor of wheel barrowing concrete and the mess driving loaded concrete trucks around the foundation does to your jobsite. We use a 6-inch pump line; one man can usually handle this, freeing the rest of the crew to level off the top of the form boards behind him. Its quick; its easy! Make sure you pump your vertical forms first with a stiff mix to about half full and let things set up a little before topping off to keep the concrete from pushing out the bottom.
Time to strip the forms, reset your string lines and layout for the mason. I like to plumb bob down and put a short concrete nail in for the corners and spray paint the angles to get the masons pointed in the right direction. This is the time to check the height of your footings with the transit for accuracy so the mason can make any adjustments early rather than later. We always make a story pole that has the top (and bottom) of the footing and a layout of every 8-inches to match the block coursing until the top of the foundation. You will now have a number for every course that you can check with your surveyor’s rod. It is easy enough in the beginning to mark the footings if you have an error that the mason needs to know about. I like the flexibility of concrete block and in this area they are used a lot, they are probably the most cost effective of the foundation choices. While the masons are working I like to have my transit set up for double checking and at this time the carpenters are preparing tees, corners and headers for the framing ahead so there is plenty to do. After the foundation walls are finished and the basement slab is poured we set up in the basement and start framing.
The first thing you will notice in the basement framing pictures, click here, is all the girders, load bearing beams, are laminated veneer lumber, LVL’s. They are strong, straight, and flat and come in a great selection of lengths and depths. They are the best thing to happen to house construction since plywood and have pretty much eliminated the use of flitch plates to create large spans without steel I-beams. All the girders at set with a string line for straight and flat with temporary 2 x 4 tees for support. The temporary 2 x 4 supports are easy to shim. This is where you win or lose on getting a flat floor system, wait until you get your floor joist and plywood sub-floor on and do a final check with a very tight string line and your transit on your floor system before ordering the supports, here we used 3 & 1/2-inch round steel posts. The floor joists are 2 x 10 Southern Yellow Pine with ¾ inch T&G plywood sub-floor glued and nailed. Before we put down the plywood we power plane the crown out of the floor joists by using a straight 2 x 4 to locate the worst joists. Lay the 2 x 4 on edge and if it rocks, plane the high joist until you have an acceptable flatness. We use power plans very often, they are great for evening out the top of girders, taking the crown out of floor joists and adjusting rafter tails after installing the sub fascia. We also use the power planes to straighten the interior walls before sheet rocking; this makes a huge difference in your final product.
The walls are 2 x 4 studs 16-inches on center, pushed, pulled and braced until straight and sheathed with ½ plywood, the ceiling joists are 2 x 10 SYP that extend out over the 2 x 4 studs and are banded at the outside. This technique allows your insulation to extend pass the inside of your wall cavity by 2-inches, increasing your thermal efficiency. The roof framing is pretty much standard stick framing, although we do spend a lot of time making sure everything is tight and right before applying the roof sheathing. We used a 2 x 8 sub-fascia that we can put a string on, dividing the difference and getting things straight often requires the use of a power plane on the rafter tails, this is where you win or lose on getting a good looking boxing and fascia job.
The center of the house is a testament to the virtues of the LVL’s ability to open up spaces. Click here.
The atrium and its associated roof load is supported by a 3.5 x 14 inch LVL on each side, the span is 18-feet. The transition from flat, at the outside wall to the angle up to the atrium, is supported by a 3.5 x 12 inch LVL on each side. The atrium roof framing are 2 x 12 rafters to allow for R-30 insulation with a 2-inch air space above for ventilation. The arches that grace the transition to this space are site built. We made patterns for the homeowner to review, she changed the kitchen entry one to be less flat, and then we use the pattern as a template for construction of the arches. The walls are 3 & 1/2 inches thick so we ripped the 2 x 4’s to 2& 3/4 inches then cut them to length and applied 3/8 plywood to each face and then the bottom of the arch. The sheetrock was then applied for a seamless look. Making arches is fun and quite easy once you learn the basic technique that I obtained from my journeys through H.H. Siegele’s THE STEEL SQUARE.
The outside of the house is dominated by the banding above the windows and doors and the appeal of the transoms above the doors and applied at the top of the windows. The horizontal 2 x 4 cedar above the windows is continuous, circling the house, garage and screen porch at this level. Below the 2 x 4 is the transom effect - the doors have separate transoms above, the window “transoms” are applied sticking on casement windows. The garage and screen porch have 2 x 4 cedar framing to carry this transom effect through. Above the 2 x 4 cedar band is 1 x 6 beveled t&g cedar with the smooth side out that is also continuous around the house, garage and screen porch, extending from the top of the 2 x 4 cedar band to the soffit. Click here.
The atrium has this banding detail above its windows also. The attempted effect of all this banding was to satisfy Margaret’s desire for “simple, clean lines”, obtain some detailing and try to counteract the busyness above the fascia line with all of its hips, valleys and the large atrium with its roofline.
Its crisp lines define the inside of the house. Having large spans and open spaces is very nice but getting those long lines straight and clean looking is a process. The essential technique employed here is good framing – we cut things to fit and if this means cutting all the rafters to a slightly different size then we do it. String lines are a necessity not a choice here. The sheet rocker also pulled a line on his long angle beads, filled in and adjusted as needed to improve the sight line; his work on the arches is beautifully done. The painter is your last line of defense and if he is not willing to put in the time an effort of doing a good sanding and final repair to the product; i.e. every inch of the walls and trim, then all your hard work up to this point will not look as good as it should or could.
The other “technique” involved here is finding subs that are good craftsman and care about the job. This can be difficult at times given the large fluctuations in the industry, the hard physical work and the relative low pay. So, if you can find a good sub that is willing to put in that extra effort needed for a first class job, treat him well.