Dear
CPT Rawles,
This
letter is provided as a reply to your reader who wrote in about
“Building Cabins on a Shoestring Budget”.
There
are two viewpoints to this reply, one from the vantage point of an
architect with a couple dozen years of real world design and
construction experience as though one of my clients was cabin builder
whom I was trying to advise, solely for a cost effective, build –
as-you-go, off grid home solution.
The
second vantage point is that of a fellow prepper, former Army
National Guard Infantry Lieutenant, and in my present role as an
Architectural Consultant to Hardened
Structures LLC,
as though the cabin builder were a client to Hardened Structures.
First,
congrats on the land acquisition. This is a great blessing. Be so
very thankful for three teen boys who hopefully can share the
workload. This will be a key to your accomplishing realistic goals.
Next, pray, and be super safe with power tools. I have had three
architect bosses over my first dozen career years that were missing a
finger or part of a hand from a table saw or something. In my very
first self-constructed project, the electrician cut his own kneecap
off with a Skilsaw.
Starting
as the first viewpoint as an architect. Before getting to my
answer, I need to disclose that I receive no compensation from any of
the brands, products or web sites listed (except in my role as an
architectural design consultant to Hardened Structures LLC.).
Homebuilding
can also be stressful on some family relationships, so expect good
days and not so good days, but others have gone your way before and
came out okay.
Mr.
Rawles is correct about the shed arranged as spoke on a wheel concept
with shed structures. I have also considered this concept for the
same reasons of affordability to getting the first structures up and
expanding as budget allows. Depending on the shed structures
selected, an octagon or hexagon gazebo kit could provide the central
space which the shed “spokes” radiate out from. This is a valid
“build as you go” plan. But just please be aware, the chief
drawback with the spokes design is the amount of wall area per square
foot of living area. Five sheds at 14’x40’ is 540 lineal
feet of walls needed to be built to enclose 2,700 SF. Conversely
a 52 foot square structure would achieve the same 2,700 SF of living
area, with only 208 lineal feet of wall to construct. So a square in
plan is our best bet to achieve the most square feet for the least
cost. So, on the build as you can afford plan, I’d steer a family
towards each unit being a 20’x20’or even 24’x24’ “garage
kit” but replace the standard roof trusses with “room
in attic trusses” in
particular Gambrel style because of the high amount of bonus living
space which can be gained in a second story under a roof you would
have to build anyway.
I
like Gambrel so much that I’ll throw out my
favorite type of shed if
that’s the route you choose (but not an endorsement of this
particular brand, just the style.)
Another
consideration which people often fail to account for in the early
stages of being an owner-builder is all the other skilled trades not
related to the shell of the house: electrical, plumbing, and heating.
For this reason it is not an invalid starting point to build
out and around and over a functional used trailer home, which comes
readymade with plumbing electrical and a heating system. On
Craigslist, a trailer still in towing condition can be found for
$3,000-$9,000. Even if the interior finishes of the trailer need a
complete rehab, this often falls within the skill set of the
do-it-yourselfer, flooring, paint, cabinets, even replacing the
lighting or plumbing fixtures is a plug and play, unlike actually
setting up an actual hot and cold water, or electrical service within
a new home. Most likely the roof on the old trailer is worn out, so
a pole barn structure over the existing roof is a very common sight
on homesteads with an older trailer.
Windows should be replaced if
they are single pane, with dual pane type.
Some
important considerations regarding cold climates:
Research has
shown that continuous insulation is far more effective than cavity
insulation. People like to think going to a 2×6 wall with R21 is far
superior to a 2×4 wall with R13, however both walls have studs at
16” on center which transmit cold straight through the wall to the
inside drywall. This is called a “Heat Sink” and is highly
undesirable. So it is actually superior to save the money on 2x6s by
building with 2×4 with R11 (or R13HD) then sheath the
home entirely with 1” of “Polyiso” type rigid foam board with a
value of R6 per inch. R11 plus R6 only equals 17, but in the real
world the R17 wall is a warmer home with less energy costs than the
R21 2×6 wall. If you live in a seismic zone then either wall will
require wood OSB sheathing directly against the studs, and the
polyiso goes over the
OSB.
Next,
research has shown that after about R40 ceiling insulation is not a
good cost investment, but foundation perimeter insulation in a cold
climate is a highly beneficial upgrade that many builders totally
overlook. 2” thick polyiso board installed against the
concrete foundation wall from top to bottom after the forms are
stripped off and before backfill will keep the cold out around the
perimeter of the house. I cannot stress enough how beneficial
this is. Think of it this way, cold air is much less dense than cold
ground, it takes far more energy to heat the ground than the air, so
don’t waste your heating with concrete touching freezing ground.
A
dilemma to struggle with for the economically constrained “retreat
shelter” is also wood frame construction versus anything else.
Up
till this point, we have been discussing Wood frame construction,
since is the most commonly known method for the novice American
builder to work with. However, this method is among the least secure
from ballistic impact and fires.
Many
other alternative construction methods are possible, but your first
hurdle to cross is the local building and zoning department
regulations. Depending on your location, this can range from onerous
to nonexistent, but please be advised these authorities have the
power to fine you daily until you tear down what you built that
violates their regulations.
Among
the nontraditional home construction methods, Straw bale construction
is an incredibly easy construction method. In my past as an
architecture instructor, I once led a design build class where the
final exam was teams of students to build outhouses. Straw bale won
the day when evaluated by a jury of local contractors and architects.
The students who attempted this project had never built anything
before. Construction by used wood pallets with foam insulation
inserted in the pallet cavity by another group of our students was a
very interesting design concept I think bears some mention as a fast
and economical construction method. There are YouTube
videos of pallet-built sheds.
Other
alternative construction methods include rammed earth, adobe, cob,
sand bag/earth bag, or earth tube. Many of these methods are very
cheap from a material standpoint, yet incredibly labor intensive.
I
am also going to mention two additional alternative construction
methods later as part of second viewpoint of this reply, that of the
e- infantry, Hardened Structures LLC representative.
As we
transition now to this second part of the reply, we would be asking
questions of what your goals are in your retreat shelter, namely:
What
are your potential threat scenarios?
What are the human and
material assets you are seeking to protect?
What is your
budget?
Do you plan to mount an active defense or do you plan to
take shelter in a safe room or shelter of some type and allow the
danger to pass before reemerging? Or some combination of both?
If
sheltering, how long do you plan to stay sheltered?
If mounting an
active defense is your team specifically trained in this role or are
you seeking training?
What equipment do you have for this role?
If
mounting an active defense what consideration have you given to your
existing topographic surroundings?
What are any special needs your
group has?
As
we go through these and other questions, we would be able to develop
an outline of solutions for your specific group, given your own known
threats. Also we would be asking if you have concerns for threats not
mentioned. For example: What are the known weather disasters to your
region? Have you considered the possibility of EMP caused by solar
flares or terrorist activity, or a regional nuclear incident, or a
localized chemical accident or attack?
The
goal is to provide a solution with no Achilles Heel, but every client
and every situation differs as to how this is achieved.
Since we
are aware that your budget plan is to self construct, it may be that
Hardened Structures role is that of an advising or design and
security planning consultant and as source for specific products for
your needs. However, for most clients, we would be performing those
services plus managing the actual construction of your shelter. Often
this is as your construction manager overseeing the efforts of local
architects and contractors.
Depending
on many factors, budget, timelines, threat analysis, site
constraints, etc, Shelters for clients can be modular units
constructed of steel and delivered ready to install on your site, or
built from structurally engineered reinforced concrete build on site
or other solutions. They may include EMP protection, provisions for
extended durations, actively filter the air from contaminants,
maintain communication with the outside world, handle human waste
safely, and even provide a home like environment where inhabitants
and relax, have entrainment and even exercise. Some clients choose a
hardened retreat shelter built to withstand the complete loss of the
home while protecting the human and material assets in the shelter.
If
in this particular case you asserted the need to protect the home
itself from some level of ballistic threat, but were on a tight
budget, there are two affordable, do-it-yourself construction methods
come to mind which may be of interest.
These
two methods are Dry
stacked masonry load
bearing walls, and non load bearing rock gabions wall infill with a
post and beam supporting frame.
Dry stacked masonry walls were
developed as a result of a 1970s US Dept of Agriculture rural housing
initiative for improving housing of persons living on Indian
reservations. Instead of skilled labor with mortar joints
between every course of block, the block walls are stacked without
mortar, totally dry and a special fiberglass fiber reinforced
“surface
bonding mortar”
is trowel or sprayer applied to both exterior and interior face of
the wall.
The
dry stacked walls are only about 70% the load carrying strength of
wet set block walls, but for one or two story residential
construction it is strong enough. Hollow block must be filled
with a solid material to have effectiveness against ballistic threats
and there are requirements for reinforcing steel which also requires
filled block.. A “dry pack” of one part sand to one part
cement to one part fine gravel with post install watering may be the
easiest method of filling block cores for the novice owner builder.
This would be done after the surface bonding mortar has cured. I
would recommend 12” block over 8” or 10” if a budget will
allow. There are “U” blocks for window and door headers, but I
have seen many 100 year surviving masonry buildings with timber
lintels in Chicago. Either an exterior insulation and stucco finish
or an interior insulation system is possible. There are merits to
each.
This
construction method, however, is a derivation of how a
Gabion fence is
constructed and is more economical than a concrete wall. The poles of
the pole barn not only provide the support for the roof, but the
lateral support for the rock gabion wall, so that the gabion
thickness can be kept at about 12”-18”. Crushed rock and concrete
are about 11 0lbs per cubic foot, and concrete is about $200 per
cubic yard. 4”
crushed stone is only about $9 per ton or
less than $20 per cubic yard.
Wire
gabions filled with stone are attractive to many people, and allow a
place for vines to grow, if that’s the look you desire, or another
school of thought is that the wires themselves are a weak link to a
persistent person with wire cutters, and they should be covered over
in shotcrete. If covering the wire with a cement, one may wish
to opt for stainless and not just galvanized wire mesh, and cover
with a minimum of 1” of shotcrete or layers of stucco. This is
because the covering of shotcrete traps moisture with leads to
corrosion, but how many years to failure is a variable, houses with
stucco over chicken wire last in San Diego a hundred years, in
Chicago, perhaps 30 years.
An
18” thick wall of 2” to 4” crushed rock gabion will defeat
nearly all commonly available small arms, with the possible exception
of .50 BMG. Added benefit of the Gabion system include, self
healing from ballistic attack; any rock damaged by incoming rounds is
crushed down by the weight of the stone above. Minor breaks in wire
can be field repaired. Gabions provide a high level of thermal
mass, which though not the same as insulation, is beneficial, but a
topic for another post.
The
roof itself must be addressed and there are several tiers of upgrade
from conventional shingles. A metal roof is a low cost fire resistant
upgrade. Tile roofs, clay or concrete are even more so. Actually
building the underlying structure of hollow core concrete panel or
“Spancrete” is a more expensive upgrade but of some ballistic
protection. A “flat” roof (actually low slope) of corrugated
metal panel with a topping of concrete, then insulation, then any of
many rubber or PVC roofing
membranes is a common commercial roof structure not beyond the skill
of most owner builders with proper instructions on
temporary shoring. This method could allow either direct run off of
water, or drains, or even incorporate a concrete block parapet wall,
which can be of tactical value.
For the very budget conscious, but
defense minded, one could envision how this pole barn and gabion
structure could be the basis for enclosing one or more used mobile
home trailers as mentioned earlier to create a “dirt cheap”
homestead retreat starting point, (see also the short book Dirt-Cheap
Survival Retreat by
M.D. Creekmore) but there is a much larger topic of “defense
in place”, and one is advised to investigate foreseeable threats
and how to respond to them.
While
this is only a primer on these topics, a wealth of information is
available with online research or by seeking out consulting advice.
I
sincerely hope the best for all your readers and welcome any
questions on the built environment and active or passive defense.
– Douglas
Clark
Douglas Clark Houzz Profile
Douglas Clark LinkedIn