The Perfect Prepper House? (Part-4)
Guest article, by ‘NRP’…
The following article covers aspects of the roof – including structure, sheathing, underlayment, materials, and roof life…
“‘Ruff’, No Blue, I said ‘Roof'”.
In my opinion the second most important part of a house, first being a good foundation/footing, is the Roof-System. I say Roof-System because all of the combination of all of the components.
You MUST have a good structure to support all of the loads.
Dead load; is the weight of the Roof-System in of itself; Trusses (supporting structure), Sheathing, Underlayment, Roofing (Clay-Tile, Shingles, Metal, Shakes) and all weight added such as the Drywall ceiling, Insulation, Equipment that may be on the roof, and so-on.
Live Load; is the loads from Snow, Ice, Rain-Build-Up, any weight that is not a permanent weight on the roof. And yes even this old “fat-boy” walking on the roof.
Uplift; the Uplift is a MAJOR factor when designing a roof system in a windy area. When wind passes over a structure (house) the wind actually pulls up on the house/roof.
A Note on Live/Dead/Uplift loads; Where I live we have a standard Dead-Load of 8 pounds per SqFt (PSF) and a Live-Load of 25 PSF. I personally take the Live-Load and double it. The house I currently have is 50PSF plus the 8PSF in an area that “requires” a Live-Load of 25#. I HATE to shovel snow off a roof if I get a freak storm that dumps 3 feet of wet snow. Every year there are dozens of stories about buildings collapsing from “heavy snow”, do not let your house be one of those stories. Normally a house is designed for a 75 MPH Wind Load causing Up-Lift. But again NRP being the nutcase that he is always builds for a minimal of 150MPH. I know that in places like Hurricane/Tornado Alley 150MPH will not be enough, so build to your area. Make sure you fasten the roof to the walls/foundations very very well. Sunlight is actually one of the hardest things on a roof; the UV’s can literally destroy the finishes on a cheap metal roof or decompose the asphalt shingles. Choose roofing that will stand the test of time.
The framing of a roof can be done in many different ways, but ALL roofs must be designed or “stamped” by a Structural Engineer. Wood Trusses are the most common style of a roof structure. Steel Trusses are also common in areas where Termites and moisture can be a problem. Red-Iron structure is becoming popular also; personally I use a combination of Red-Iron and Steel Trusses.
This usually is a layer of either Plywood, OSB (Oriented strand board), or Steel that spans the structural members (Trusses). Standard “code” is 7/16” OSB, again I use 5/8” for two reasons. One I’m a fat guy and I hate a “spongy” roof when I need to access the roof. Second if you use Shingles, Shakes, or Tile you will be nailing the materials to the roof sheathing, the thicker sheathing the better to hold the roof down. Nothing worse that shingles blowing across the yard in a wind/rain storm
Most homes use 30# Felt, or “Tar-Paper” I prefer using a product called “Titanium® UDL25 – InterWrap”. It’s a LOT stronger than Tar-Paper and will last uncovered, if needed, for quite a while. Whatever product you use be sure to think of this layer as the “roof”, meaning it should withstand the weather (rain, snow, sun, wind) without the final roofing. Its purpose is many fold, it acts as a “slip sheet” between the roofing and the OSB, it acts as a secondary water barrier.
There are literally dozens upon dozens of different materials on the market to choose from. Asphalt Shingles, Wood Shakes, Single Ply, TPO, PVC, EDPM, Asphalt-Built-Up, Clay or Concrete Tile, Metal roofing in many different styles.
Personally I will be choosing a good “Standing Seam” metal roof, here is why. ALL roofs will move around a LOT from the extreme temperature changes, a normal roof will expand and contract around .5 to 2% on a normal day. If you have a black or dark colored roof you may have even more movement. Additionally this movement may not be uniform, when the sun hits a roof and there is a tree shading one part, the roof will not expand evenly. Amazingly the amount of movement does not tear a roof to shreds.
The “life” of a roof, Asphalt roof may MAY last 10 years, even with a 30 year warranty they will NOT last that long and just try to get a company to repair a roof after 10 years, good luck. Tile and Clay, well lets just say…. NO. Metal “R” panel style roofs are fastened with screws through the face to the underlayment below. Is putting holes in a roof a good idea? Then take into account the moving of the roofing, the holes WILL become elongated and leak, period. A Standing Seam Roof (SSR) has a clip that is fastened directly to the structural member below the sheathing, making the fastening of the roof much stronger, this clip stands from 3-5” above the sheathing, than the metal roofing is crimped or snapped to the clip with no penetrations in the roofing. This is a very watertight roof membrane. And has a very high uplift resistance.
I always have a tendency to “over-build”, there is a reason for that. I don’t care for making weather related repairs on my home, it’s costly and foolish if I did not build it correctly in the first place. In my opinion the extra cost in building or over building correctly is money gained in the long run. The roof is NOT a place to skimp on building or cost.
What experiences have y-all have with Roof-Systems? Anyone have a roof blow off during a wind-storm? Maybe a very bad leaking roof? Dry-Rot on a poorly installed roof? All can be very expensive to repair/replace. My thoughts are to build very well once and avoided the repairs if possible.
Building your home should be a good experience. If you do it yourself or have a contractor, make sure to relax, remember it’s a house, NOT a home, you and your family are the difference, it takes more than a pile of wood and concrete to make it so.
Perfect Prepper House Part-1
Perfect Prepper House Part-2
Perfect Prepper House Part-3
Perfect Prepper House Part-4
Perfect Prepper House Part-5
Thanks for the article NRP. I need to replace my roof, and you are right, 30 year asphalt shingles lasted me 20 years, and they are curling and breaking corners now. I don’t have the company name or original receipt because I bought my home with shingles on, but there is a company that sold faulty shingles locally. They were sued so those who had receipts got money from the bad shingles for replacement.
So now I am saving money this year to have a steel roof put on. I am changing because I have to normally sweep the roof from needles and limbs, clean the chimney, and shovel snow on the roof to prevent ice dams created in my extreme weather conditions. I don’t have a steep roof, but gently sloping one. I wondered if a steel roof would eliminate the snow shoveling and sweeping debris off, being a slicker surface? I need your expertise.
Stardust, I deal with roofs for a living, among other things, and what you have described sounds a lot like organic base mat shingles, as opposed to your typical fiberglass shingles. Organic base shingles have a fiberous look to them. Typically on the south facing roof fields will deteriorate much quicker and lose their granules faster than the other roof fields mainly due to the thermal changes. Fiberglass shingles resist this deterioration much better. I am also familiar with a company who was under a class action law suite for bad shingles so here is what you do. I suggest you go to the CertainTeed website and read about all of their warranty information. They will actually describe how to take a sample shingle off your roof and send it in. If it is one of their faulty shingles in the suite they will cover the cost of materials, I am pretty sure, for a new roof. You may also be able to talk to a respectable contractor who deals in roofs and they might also be able to assist you in taking and sending a sample shingle in for analysis. It is definitely worth a shot to check.
My area requires a roof built to withstand a snow load of 80 lbs per square foot. A steep metal roof works best here to shed the snow – but there are some things to be aware of. If you have plumbing vents, electrical mast, chimney etc they can be damaged by the ice and snow sliding down the roof. Some roofing companies install guards above such roof penetrations – my choice was to have no vents through the roofing but out the side of my chimney box. I also have an interior ladder system leading to the top of the chimney box with a flip up lid so that I can clean the chimney at least twice a year. With this system I do not have to climb on a steep metal roof, build a ladder on the roof, or rent equipment to reach the chimney. One more word of caution – do not stand or walk under the sides of a metal roof with snow as this can avalanche onto your head. Very heavy. In my case, I had three rows of snow stops installed on each side of the roof to prevent the uncontrolled sliding of snow but the down side is that the snow stays on the roof and melts slowly – constant dripping.
Excellent point, If at all possible have all “needed” penetrations out the gable (end) of the roof system. Plumbers like to run vent pipes straight up and have 3-6 or more “holes” in the roof, do NOT let them do that. As far as a fireplace or wood stove chimney the design of the house could allow the chimney to go directly through the ridge (top point) making it better to flash.
Personally I do not put snow stops on my roofs, I want the snow slide/fall off.
Another thought about steel or metal roofs is that your insurance company may give you a better rate for fire coverage.
The fire safety of a metal roof is negated if you install a gutter system that collects combustible materials like leaves and evergreen needles and is not clean out regularly. In our area so many gutters have been torn off by sliding snow and ice that most have chosen to have no gutters or very limited to where people need to walk.
If your location is in hurricane zone, spend the extra money for ‘hurricane ties’, the steel brackets that secure your roof joists to the top wall plate running along the edge of your wall. Codes require them every other joist.
These hold the lumber so that in case your roof and plywood deck blows off, it is a matter of replacing on the plywood, vs. labor or installing new roof supports which takes much MUCH longer.
Also make every attempt to have adequete attic vents. That heated air space held next to your ceiling radiates down, causing your A/C bill to skyrocket. Many codes now require that placing rigid insulation on the roof deck outside to keep heat from invading the attic space. They also manufacture a radiant heat shield that nails on inside of attic against the joists, but some think that holding the heat against the deck actually ‘cooks’ your roofing system, causing premature failure.
Keep any trees / branches from sweeping your roofing – causes premature wear to surface. Homebody’s point is well made – they do manufacture no clog gutter covers (gutter guards ?) which prevent build-up.
Thank you again NRP for the hard work – really enjoying the series.
Not to belabor the point about gutters or no gutters – since most ice build-up on a roof is from melt during a warm or sunny spell followed by freezing at night, the ice usually forms at the eaves. Any water in the gutters also freezes and forms a solid mass with the ice dam at the edge of the roof – this all slides off taking the gutters along when temperatures heat the metal to the point that the ice lets go.
Freeze/thaw cycles are a pain. I would prefer constant below freezing or above 32 but someone up there calls the shots always.
@ j.r. guerra in s. tx.
Good call on the hold-down straps, here we are required by the IBC (International Building Code 2009 version) to install H1 G90 Hurricane Tie ever other joist. I believe this is becoming the Code for the rest of the US as well. I would go a little further and strap the studs (every-other or 32″ OC) to the stem wall as well.
You also mentioned vented attic space, I personally make the attic space heated (Great Storage), so place all insulation at the roof line. Additional 3-4″ of ISO on top of the decking is also a good idea. with a good R-38 Batt or Spray-Foam in the top-cord of the trusses and 4″ ISO on the top, your talking R-38 + R-23.8 = R-61.8±. Walls I do 2X6 Steel Stud framing plus 2″ of ISO in the stucco system, so R-19 + R-11.4 = R-30.4±. so yes a very well insulated house. FYI IBC Code is R-38 ceiling/roof and R-19 walls. Now add a good set of triple glazed windows and Insulated Steel Doors, and you have a very nice house and easy to heat/cool.
One more comment on gutters, even with the no-clog gutters, dirt/slit “can” still build up in them and fail/fall. Now if your going to do a Rain Catchment System you will need a good gutter, do not skimp on these, buy them from a commercial supplier, not Home-Depot. And clean them out often. As far as freezing gutters, I have seem people with a LOT more money than me install “Heat Trace” in the gutters preventing them from freezing. Not my cup of tea, but whatever. Personally I do not do gutters and forgo the rain-catchment until spring/summer and use a removable system. Winter is not the time to try and “catch” water off the roof, well maybe catch some ice and snow????? :-)
Good comments NRP
I chose to not have an attic by building with scissor trusses thus gaining a second floor with a vaulted ceiling. The low headroom areas to each side provide storage space. Yes, I too have invested in abundant insulation – R50 ceiling and R22 walls. Windows are triple glazed. Even in 90-100f heat, the main floor (slab on grade with in-floor heating) never exceeds 72F. The extra investment in quality construction and insulation will pay off in the long run.
Our construction methodologies are similar NRP. As a team, we could build wonderful structures but maybe our redundancies would put us in the poor house (ha ha)
I agree NRP. I could never understand how a builder could build a house that will stand for 200 years but you have to replace the roof every 20 years or so. When we built I wasn’t as concerned about the roof so it was asphalt shingles. I remember installing the insulation in the attic and just looking at all the nails coming through the roof from the shingles. It just didn’t make sense. Something that is supposed to keep the water out and yet the first thing they do is fill it full of holes. These shingles were rated for 30 years but after one particularly bad winter where we actually had to shovel the roof (a first for us) we had lots of damaged shingle. No leaks yet but we knew it was time. They lasted 25 years for us. I had researched and had decided on a metal roof for its longevity. So that is what we did three years ago.
One problem with this design…. The walls are not bullet proof…
So you go to the next level of protection – cost over 1 million. Then the bad guys bringing heavy equipment. So you go to the next level of protection – cost 5 million. It never ends even in a fortified bunker way underground – then you eventually come up to a burnt out place with no way to carry on.
Were do you draw the line? Unless you define the goal, you will forever be stressed about not seeing the end.
If you can’t afford the ballistic materials to build such a structure then you work around it. Make a ballistic safe room, or a hidden escape hatch that exits far from your house. Remember, if they don’t know where you are, they can’t shoot you. Hide and evade is a viable solution.
Well I wish I knew all this stuff when I had my cedar shake roof replaced with a “50 year” asphalt roof about 8 years ago. My rational was I might outlast a 20 year roof, unlikely that I’d last longer than a 30 year roof and went for the 50 for resale value for the kids. Anyway my finances are not going to allow me to replace it and I do live in a rather mild climate. Not to windy (tucked into a bunch of Redwoods) Seldom gets into the 80s and rarely freezes. Occasional small hail. But what can I do about moss? It’s really getting to be a problem. I do have a rain catch system so I’m concerned about unfriendly chemicals. Suggestions anyone?
Moss, that’s a problem my mom has, she lives in “fungus corner” OR. She has a light solution of bleach sprayed on the roof once a year, that seems to take care of it. There are a lot of other “sprays” out there, but again chemicals are the biggest problem
Weird question (my brain does that). If there is uplift on the roof when the wind blows over it, could that be used? Maybe for power generation? Reduce uplift at the same time, likely.
Not a weird question at all, Wind generators are a great idea, but for them to work well you need a fairly constant breeze/wind. I doubt if the added velocity of the wind caused by the obstruction (house) would significantly increase the wind velocity to operate a WG if you already don’t have that capability. If all that gibberish makes since. :-/ So basically — No.
Excellent article NRP. I added hurricane clips (Simpson StrongTies) to my roof system to prevent any uplift. They were an inexpensive extra “insurance” policy that only took me and my son a few hours to install.
Looking forward to more construction related articles!
God Save This (once) Great Republic!
Enjoyed the series, but thought above ground ICF walls could have been discussed more. It is more expensive than wood frame, maybe 20% more, but it will pay for itself with the increased energy savings over time. Building a livable home for offgrid/disaster situations has to start with energy efficiency, because no matter what the source of your energy is (electricity, propane, wood, etc) you’ll want to use as little as possible since you may only have as much as you can store onsite. Beyond energy efficiency, there’s the added structural integrity of ICF. Just google “icf tornado”, “icf hurricane”, or “icf earthquake” to find images of whole subdivisions destroyed except for the ICF homes. Keep searching and you’ll find cases where they remained standing after being struck by trucks/SUVs. Fire resistance is measured in hours instead of minutes. They’re nearly airtight, making a whole house air filtration system easy to add. They’re rodent proof and sound dampening. Then, of course, is their ‘projectile resistance’. A flat wall ICF with an 8″ concrete core will stop anything up to a .50 cal with armor piercing ammo, .308 or 30.06 doesn’t have a chance of getting through even after repeated hits.
We built a 8″ ICF home almost 10 years ago, and I’ll never live in a stick/brick home again. Insurance rates are cheaper too, and banks generally understand the additional cost when it comes to financing it unlike some other non-standard home construction types.
Valid comments Walt
Material and labor cost are considerably higher than stick framed. Hidden costs are in running and installing electrical wire/outlets, plumbing, vents (furnace etc, application of wall board in some cases, application of exterior finishes in some cases.
I have also seen several cases where the cores were not completely filled, particularly under window openings. Best way to check is with an ice pick or similar tool.
I believe the insulation for most of these systems is around R22 to R24. There may be better ones out there now.
you will get no arguments from me on Ice-Block construction. I have worked on a couple of them in my years and will admit the first I built 20-some years ago was a BITA, now they have all the corners, tees, ledgers and such premade. As you said not cheap though, and the long run they will save money. Unfortunately most builders are only in for the short run, build it and sell. Your will probably never see an Ice-Block house in a subdivision unless the owner built it.
As far as a owner/built, you bet I would suggest using Ice-Block.
The roof is what keeps out the elements.A metal roof (standing seam) is a great system.They will leak (badly) if not installed correctly. NRP is correct about getting the right installer.Not all roofers are metal roof installers.metal roofs require a different skill set.keep your penetrations to a minimum.Walking on roofs does create problems especially metal roofs.That’s why i prefer to install solar panel arrays on the ground instead of on roofs.Just put a chain link fence around your panel arrays to keep out curious critters.When maintenance and service needs to be done it’s much easier from the ground then walking across the roof.
Simpson Strong tie systems should always be incorporated in your roof system. IBC?UBC codes require it nowadays.
Another thumbs up article NRP.
@Bill Jenkins Horse
I agree Bill, keep everything OFF the roof. The company I work with does a ton of insurance work (among other construction), 75% or more of the insurance work is from damaged roofs alone, (walking on the roof), Swamp Coolers that leak, Broken/frozen water lines in the attic, and I’m talking $millions of damage.
My advice, build a “good roof system” and stay the heck off of it, period. Ohhh and trim up that tree that’s leaning over it. a nice 6″ diameter limb will go right through the roof with all the water and snow with it. Last one we fixed was well over $23K (the tree ended up in the kitchen) plus the damage to the personal property.
OSB = junk. Spend the extra money and use plywood.
Upon moving to my current BOL, I was very happy to discover construction photos which revealed all plywood underneath the roof and behind the exterior cedar boards. My experiences with OSB has been less than impressive.
Certainly we appreciate all comments and opinions, It would have been interesting to hear why you believe “OSB = junk”, I have found that usually a past experience such as Ken and probably yourself obviously has had usually sways the thinking. One would probably need to look at the application and why the OSB may have failed. Don’t get me wrong I’m not a 100% die-hard for OSB, but in my experiences 99.99% of the failure of any product is the fault of the instillation or maintenance of ANY product, not just OSB.
But not knowing why you think this way does not really help the conversation. No different than me saying a “Ford is junk”, “an AK47 is junk”, or “Asphalt Shingles are junk” without know why I feel that way kinda leaves the discussion at a dead end even though I feel that way.
Thank you again for your input.
As a 4th generation, lifelong roofer…. Piece of Advice for roofing. Look up Decra or Gerard stone coated metal roofs. They are made to look like shingles, tile, or shake. I’ve been in hurricane disaster zones and the only roof left are these. I’ve seen whole towns burnt down by fires and the houses with Decra or Gerard on it, are the only ones standing. Class 4 rated (against 2.5″ hail) and will get you a discount on your home owners insurance, up to 29%, depending on where you live and your insurance company. It’s expensive, but it will be the 1 and only roof you ever put on in your lifetime.