Owner's Manual
The following is the ROUGH CARPENTRY section of our Owner's
Manual. It is provided here as an example of the general content of the
book. Unfortunately, we can make this book available only to our customers.
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ROUGH CARPENTRY SPECIFICATIONS AND NOTES
FOUNDATION DECK (1ST DECK)
It is very important that this first laying on of wood be done with precision.
The precut frame that will be erected on this deck cannot easily be adjusted
to accommodate work that is not level or carefully dimensioned. The plans
and sill details will give the material specifications, but there are several
alternatives available. Assuming that the slab has not been poured, lally
columns (concrete filled steel tubes), are your best choice for posts.
These usually come supplied with 3-1/2" square plates for the top and bottom
of the column. This is adequate bearing surface on top of a concrete pad,
but should be enlarged to 6"x 6" where it contacts the wood girt. If the
basement is to be used as living space, then heavy timber posts and beams
similar to those of the house may be used. In this case the slab must be
in place before installing the deck since it is not recommended that concrete
be poured around wooden posts. It is possible to install a post and beam
wall on a walkout basement before pouring the slab because the posts will
be up on the frost wall. It is also possible to place solid 4" concrete
blocks under the wood posts and on top of the pads and then pour the slab
at a later date, but it is very important to pour the pads at exactly the
right elevation so the bottom of the wood post will be at the same level
as the top of the finished slab. Although this deck is conventionally framed,
there are many details that are unique to our system of building. Care
should be taken to be sure the electrical raceway, post blocking, stair
and chimney openings and over-all dimensions are correct. See details RC/S1
thru RC/S4
EXTERIOR TRIM SPECIFICATIONS AND NOTES
The architectural or esthetic success of your building is determined by
it's shape, proportions, fenestration (window arrangement), and how it
is trimmed. Buildings with the same shape and proportion can be made to
look either contemporary, Victorian or traditional depending on how they
are trimmed. A traditional building that looks flimsy and cheap can almost
always be improved just by changing the way it is trimmed. Trim should
add texture, shadow line and balance to your structure. It should not be
nailed on just as a way to deal with ends of your siding or to hide rough
framing.
ROOF TRIM
Once your stresskin panels have been installed, the next job should be
to trim and shingle the roof. Roof trim should protect your panels from
the elements, support the roofing and add texture and shadow line to the
rakes and eaves. The amount that a roof overhangs the walls and the pitch
of the roof can have a lot to do with the architectural "look" of your
building and will influence the kind of trim you choose to apply. Examples
of basic roof trims can be found at the end of this section in details
RC/R1 - RC/R3 ROOFING The roof is usually the largest single area of the
building exterior and should be given careful consideration both from a
structural and architectural or esthetic points of view. The most common
type of roofing material is the fiberglass mat asphalt shingle. They are
available in many colors, patterns and thicknesses. The standard pattern
is three 12" tabs with 3/8" cut outs between them and is installed with
5" exposed to the weather. The way that the cut outs are aligned on progressive
courses of shingles can produce quite different effects to the finished
roof. Shingles are also available with scored marks instead of individual
tabs. These are supposed to last longer and tend to give a roof less texture.
Architect grade fiberglass shingles have a double thickness and random
pattern to their tabs that give a very noticeable texture similar to a
wood shingled roof. Stresskin panels create a "hot" roof as opposed to
the "cold" roof of conventional stick construction. The roof venting in
conventional construction serves the purpose of removing moisture that
accumulates above the fiberglass insulation batts and at the same time
keeps the outer roof sheathing cooler on hot summer days. Winter ice dams
are also reduced on a vented roof. Stresskin panels with urethane foam
cores are excellent vapor barriers and moisture will not penetrate them,
provided that the joints are properly sealed, so vent spaces are not needed
for moisture control. This is a great advantage in simplicity of construction
and in fire safety (vent spaces act like chimneys and cause a fire to spread
quickly), but it lacks the cooling effect of a moving column of air under
the roof sheathing. Therefore, it is important not to use black or very
dark colored shingles on a stresskin roof. Most shingle manufacturers will
not guarantee their product on a "hot" roof. Thinner (bottom of the line)
shingles have a tendency to show the panel joints as the higher heat of
a hot roof causes them to conform to the roof. This has never occurred
on any double thick "Architect Grade" shingles that we have installed on
our stress-skin panels and we therefore strongly recommend this grade of
fiberglass shingle. With snow accumulations of a foot or more that remain
on the roof for over a week, ice damming may occure especially under skylights.
Bituminous ice and water shield will prevent water from penitrating the
roof. Roofing paper is not recommended on stress-skin roofs because it
will expand and contract too much with extremes of hot and cold. Bituminous
ice and water shield should be installed on the first 3 feet of
the roof eaves (more on shallow pitched roofs), in valleys and around all
skylight openings. It is very important to follow the manufacturers installation
instructions (with the exception of roofing paper) and be sure to leave
a space (1/8") between each individual shingle. Many times installers will
not pay attention to this detail and expanding shingles can buckle in the
heat. There are thousands of shingled stress-skin roofs that perform perfectly,
but the higher temperatures of this type of roof requires extra attention
to these installation specifications. It is possible to vent a stresskin
roof by adding verticle strapping and another layer of plywood that is
vented at the ridge and the eaves, but our experience has shown that this
extra expense is much greater than that of the "Architect Grade" shingles.
If your situation might involve extra high levels of moisture (indoor swimming
pool, greenhouse, etc.) or deep snow layer on the roof for most of the
winter, then you should consider venting your roof. Wood shingles are another
popular but expensive option. Use only western red cedar, installed on
horizontal strapping to allow the undersides of the shingles to breath
and be absolutely sure that whoever installs them follows the manufacturers
instructions to the letter. Raised seam and other types of metal roofing
works very well on stresskin roofs, but it is not always easy to locate
experienced installers and can also tend to be expensive.
INSTALLING WINDOWS AND DOORS IN STRESSKIN PANELS
The rough opening for a window or door in a stresskin panel is the same
as conventional construction with the exception that the drywall is already
installed. This can be used to advantage when installing windows and doors
because the jambs can be perfectly aligned with the drywall surface. This
will be a great help in the installation of the finish trim. When positioning
a window in it's rough opening, the bottom should be set on a pencil or
similar object. This will allow one person to easily center the window
level in the opening and at the same time create a space for sealing foam
to be blown in. Once the exterior trim or nailing flange of the window
has been secured to the sheathing, the window jamb can be aligned with
the drywall surface in the following manner. Cut several lengths of strapping
or any 1"x 3" wood scrap 12" longer than the width of the rough opening.
Position these pieces horizontally across the opening about 2' apart. To
push the window out, screw the strapping only into the 2x4's that frame
the rough opening. To pull the window in, screw the strapping only into
the window jambs. When using Andersen casement or other windows with loose
extension jambs, align the jambs flush with the drywall and nail the extension
jambs to the rough opening using shims as necessary. Once the window jambs
are flush with the drywall surface, non-expanding urethane foam is blown
into the space between the rough opening and the window jamb. When the
foam has cured the strapping can be removed. It is not necessary to nail
the window jambs into the sides of the rough opening except as noted above
with extension jambs.
OTHER EXTERIOR TRIM
Corner boards, frieze boards (under the eaves), rake boards (under the
gable overhangs) and window trim are the usual trim on most residential
type of buildings. A building could have all of these trim elements or
none of them. Generally speaking most trim boards on tradition style structures
will look better when they are thicker and wider. Thickness can often be
achieved by building up more than one layer of material. Width usually
means using wider stock. Blocking for light fixtures, meter sockets, etc.
should be located before installing siding. It is recommended procedure
to staple building paper to the sheathing before applying trim boards.
The paper should extend completely under and 6" beyond the edges of the
trim. When horizontal siding such as clapboards and wood shingles are used,
the bottom of this paper should lap over the top of the unexposed portion
of a piece of siding so that any water that penetrates this joint will
run out between pieces of siding and not under the siding and along the
sheathing. When siding is butted against the trim, this layer of building
paper will protect the sheathing from any moisture that might enter this
siding/trim joint. This is especially important on verticle siding / trim
joints. Please refer to details RC/T1 - RC/T4 and RC/W1 - RC/W3 All millwork
and trim should always be painted, not stained. Stain will not offer enough
protection to prevent the wood from moving and causing the joints to open
and let in moisture. The back sides of all trim boards should be primed
before they are installed for the best long term protection against the
elements. Back priming will prevent cupping that results from unequal expansion.
SIDING Siding refers to any material that is used to protect the sheathing
from the weather and to give the building a finished appearance. Siding
can be applied horizontally, vertically or diagonally. Horizontal application
will visually widen and lower a building facade while vertical application
will have the opposite effect. The material most commonly used for horizontal
siding is clapboards (also called beveled siding). Vertical siding material
can be tongue and grooved (with or without a "V"), shiplap or board and
batten. Wood shingles will give a strong horizontal line and a weaker vertical
line. The preferred wood to use for siding is quarter sawn or vertical
grained. This wood is cut from a log along a radial line such that when
you look at the end of the board the grain will run in parallel lines across
the short dimension and the face of the board will show equally spaced
parallel grain lines. This kind of material will warp less, weather better
and hold paint and stain longer than flat sawn wood. Siding that will be
stained should be installed with the rough side to the weather because
this surface will absorb and hold more stain. Paint should be applied only
to smoothly planed surfaces. Siding that is stained or primed on both sides
will give much longer service, especially on flat grained siding. Staining
or painting siding before it is applied is the preferred method. There
are some companies that will pre-stain or prime siding with the product
of your choice. Your supplier may know of some in your area. This is also
something that many owners do themselves to save money. Material can either
be brushed on or dipped in a trough. Dipping is faster and uses more stain
and will give the better result, but only works with more viscous stains,
usually transparent and semi-transparent. Wet boards can be set to dry
on edge between rows of closely spaced finish nails driven into a pair
of 2x4's. When applying siding, it is strongly recommended that stainless
steel annular or rings nail be used. Always be sure to use a nailing pattern
recommended by the manufacturer. Most lumber yards will have this information.
Thicker (usually vertical) siding should be applied with rust resistant
drywall type screws if the material is over 4" wide. Where siding butts
up against trim boards, a bead of silicone or urethane caulking should
be applied to the joint where the trim board meets the layer of building
paper. This caulking is applied just before the siding which is then pushed
into the caulking. This will effectively seal the joint while also protecting
the caulking from the elements. Infiltration barriers such as Tyvec do
not need to be used to prevent infiltration but are recommended in areas
of high wind to protect the sheathing from water forced through the siding.
Properly installed stresskin panels are already tight enough to prevent
air infiltration.
INTERIOR PARTITIONS
Material used for interior walls, closets etc. should be kiln dried and
protected from the weather. Many lumber yards will leave open lifts of
material out in the weather and wet studs are very likely to twist as they
dry, causing drywall screws to pull in and door openings to miss-align.
Steel studs can be used also, and will become more commonly used as the
price of framing lumber increases. The interior walls of a timber framed
structure are not load bearing and therefore simpler to build. The plate
on the top and the shoe on the bottom need only be one layer thick. Unless
otherwise indicated on the plans(such as in a plumbing wall), partitions
should be centered on the framing. The maple splines of the timber joinery
should not be cut out where they project below the beams. The top plate
of the wall should be stopped short of the spline. Walls that must reach
up to the ridge, are stronger if constructed as one wall set on top of
the other. The lower half of the wall should have a continuous double plate.
The top piece of this plate can be a 2x 8 that has a radius routed on either
edge and will extend beyond the drywall. The upper half of this tall wall
is built with the 2x4's set flat to make a wall 1-1/2" thick. This thinner
wall will not bury the braces on the ridge. The 2x8 board will trim the
offset in the wall thickness. Closet walls in cathedral ceiling rooms should
be framed only 7'-6" high. This lower height will make the space feel bigger
and give easier access to the closet top for plants, decorative pieces
or whatever. Blocking for towel racks, cabinets, etc should be located
and installed before drywall is installed. Please refer to the details
at the end of this section. RC/P1 - RC/P7
MORE NOTES ON INTERIOR PARTITIONS
It is important that you understand and discuss with your carpenter the
locations of the following:
- EXTERIOR BLOCKING FOR: Electric meter sockets, lights, vents, etc
- INTERIOR BLOCKING FOR: Stair trim, drywall, cabinets, towel racks,
medicine cabinets etc.
- MECHANICAL RUNS FOR: Heating ducts, ventilation ducts, plumbing,
gas, electrical
ROOF CRICKETS
When two roofs intersect and do not have the valleys exposed from the living
space, it is necessary to create exterior valleys by building a stick built
cricket. It is important that the spaces created by these crickets be ventilated.
Ventilation of these spaces can be done with two low profile domed units
located on the back side of the cricket, one near the ridge and the other
near the eave. It is important that these spaces be well sealed from the
building interior before the crickets are built.
PORCHES AND DECKS
Please refer to details RC/D1 - RC/D10 for information on attaching decks
and roofs to stresskin panels.
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