Monday, January 26, 2015

Roof Trusses



All about Roof Trusses

A Common Residential roof truss is made up of 5 parts. 
1. The Roof Rafter on which roof sheathing and finally roof surface is attached
2. The ceiling rafter on which the ceiling surface is attached
3. Bracing tying the two elements together into geometric supporting structure.
4. The Truss Tail which is the extended portion of the roof rafter protruding past the wall creating an overhang.
5. Connection plates which are steel plates with barbs punched one way through the plate, creating a connection of two members when this plate is forced by machine into the surface of the two members.

Since local energy code requires about 12” of insulation in our area (using batt style) to meet the minimum R-38 requirement we have to examine how different kinds of trusses affect this ability to insulate (mainly over the wall where the two members meet). Ever see ice dams on the eaves of houses?  The Economy truss is the main cause.

Common Residential Truss types (3) shown
Left: Economy Truss (poor): has the minimum amount of wood required to attach the two members
Center: Max Butt Truss (better): Raised heel gives more height for insulation
Right: Energy Truss (best):Raised heel gives full height for insulation

Note: raised heel trusses are more expensive.


 


Monday, August 18, 2014

Where to put the money when designing a home?

Where to put the money when designing a home?

When designing a home, there’s always a thousand things you want. The reality is there’s usually a budget. These are some of the most important things to plan right from the start that are expensive to change later.

      1. Design  Make sure you have a bit of room to grow in your new home and most importantly make sure it’s in the location you want. Also if you purchase a home plan that shows stone columns and an arch over the front porch or a dormer over the garage or some other design element that you decide to change, spend the time and ask your draftsman to draw your idea up for you. It’s very easy to do a quick front view to see what it will look like. If you don’t, you might have a hard time re-selling the home later. I've seen this first-hand with small builders doing spec homes. They skimp on some of the exterior design elements and can’t sell the home because the lacks the curb appeal it was meant to have.
      2. Foundation  Talk to your designer and make sure they meet or exceed the recommended reinforcing  for your foundation. No one wants a leaky basement. Though concrete most always does crack, make sure the waterproofing is the membrane type adhered to the exterior side of the foundation prior to back-filling. While your have the wall open make sure the footing drains are properly installed.
      3. Floor Joists  Talk with your designer and make sure the joists specified are not at the maximum capacity for the span.  It’s also worth mentioning  that open web floor joists, though costing more up front, save your sub-contractors time and you space by allowing many of the mechanical s, plumbing and wiring to be routed through the web instead of below or worse yet drilled through. Ask your builder if some of the added cost can be recovered with lower bids on mechanical installations like plumbing, heating and electrical.
      4. Sub-floor  3/4” OSB (oriented strand board) is typical and tongue and groove is standard but make sure it’s also glued with construction adhesive and either nailed with 2” or longer ring shank nails or screwed down.  If you miss either of these you’ll probably end up with squeaky floors later.
      5. Quality Insulation  Spray foam Insulation, open or closed cell. The cost of energy is not coming down and spray foam insulation costs are. This is one item that will pay for itself very quickly. Spend the extra money and do the attic floor too but don’t get talked into doing the underside of the roof unless you plan on finishing that space. You don’t want to heat any more area than necessary. Remember wherever you heat you also need ventilation because with heat comes moisture. If it’s a dead area that’s warm but doesn't have any air flow, you’ll eventually have mold or mildew. Speaking of air flow, make sure all the vents (bathroom and range hood) are vented to the exterior. Also no bath vents should vent to the eaves. The warm moist air will rise back into the attic and create mold.
      6. Quality windows and doors  There's a big difference in windows. Beware of vinyl. Not just because they’re vinyl but because:
A. There’s so many vinyl window manufacturers to choose from, good and bad very few have a long track record to rely on.
B. Because vinyl is expands and contracts, which means proper installation is crucial.
Windows are a big part of the cost of the home for good reason. They’re essential for energy efficiency, look and function and cannot be easily changed later. Too many people I know have nice homes with vinyl windows that don’t work very well. If you're planning vinyl windows, do your homework. I recommend avoiding them all together.
      7. Quality trusses Yes that’s one you don’t hear much about. Here’s the thing; at the roof edge where the truss extends out to the overhang is where the truss is the thinnest. An energy truss costs a little extra but adds some height here (called "heel height": top of the wall to the bottom of roof sheathing) so you have room for the recommended insulation where it’s most important. That’s why so many homes in colder climates like Michigan have ice dams. It’s not uncommon for an economy truss to be 4” or so at this point. If the recommended insulation is about 12” to get R-38-49, you see what I mean. Warmth reaches the underside of the roof through this thin area of insulation, melts the snow, freezes to ice, then melts, re-freezes and up the roof it goes right under the shingles. This is also why ice and water shield protection is also so important (and required by code).
      8. Roof sheathing  7/16” roof sheathing is barely enough to span 24” even with clips. All of my house plans I call out 1/2”. I've walked on enough roofs to know that roofs with 7/16” sheathing feel spongy and I've seen several even sagging between the trusses. If I were going to build a new home right now, and I had a little extra money in the budget I might even use 5/8" plywood. 1/2" is acceptable, but minimum. 
      9. Heating Systems If you can afford to go with Geo-thermal with hydronic radiant floor heat, that’s the most comfortable in my opinion. Forced air is most typical and within budget for most of us but if you're building the home of your dreams, spend the money now. Energy costs are not going down. Heck why not consider a zero energy home. Wind, Solar.....Hot topics right now so do some research.

Delay Other Upgrades if necessary Things like solid surface counter tops, hardwood flooring, wood shelving, crown moldings and built-ins are all things that can be upgraded later without too much trouble. Same goes with finished spaces like the basement and garage, both of which can be done later as well. 

Tuesday, August 12, 2014

Pros & Cons of Foam Insulation



Having recently built a small home, we decided to spend some extra money and install foam insulation instead of batt. Though batt insulation has been the standard in our area for many years, is inexpensive and easy to install, it has limitations; mainly insulating value, but equally important doesn’t have the ability to block air flow like foam. Air flow is not usually regarded as a factor when talking about insulation but with air also comes moisture and possibly mold. Also moisture reduces the insulation “R” value of batt insulation.

So now on to Foam insulation; and I’ll admit I don’t know everything, but this is my experience and so far what I know. 1st there’s open or closed cell. Being just that, one has closed cells not letting any air through and the other open cells which allow a small amount of air through (negligible amount in my opinion). Closed cell is more expensive and weighs more per s.f. but blocks air flow completely. Closed cell is also hard when cured which creates a structural advantage by locking the framing in which it’s installed together. It’s also a bit harder to work with and the contractors we talked to said they almost never fill the entire wall cavity full with closed cell; partly due to cost and partly due to R-Value. They say install an inch or two and fill the remainder with batt. They say by doing that you get the air barrier and also the R-Value you need. Speaking of R-Value, you can get the specifications of each on line, I won’t spend the time here to go into that, basically closed cell is a bit better but both do degrade some over time.

We chose open cell foam because we didn’t want any airspace in our walls and it’s less expensive and in my opinion a little more environmentally friendly, not off-gassing as much as closed cell. My understanding is many companies are creating more environmentally friendly foams now, but you’ll have to do the research when you’re ready to purchase. One other factor for us was the fact that open cell foam is still soft when cured and easy to patch, dig into and re-fill if say you need to modify some electrical wiring in the wall or something. You just buy an applicator gun and some small cans of the foam from local suppliers and do it yourself. I think the cans of foam were $10-$15, not at all expensive. Not the same stuff as the foam you buy at the home centers though, At least not yet.

One other factor for us was that our small home has a hand framed 2x10 roof with 2x6 Shed dormer and the bottom side of the roof rafters is our ceiling. It’s not possible to get enough batt insulation into a 2x10 ceiling let alone a 2x6 so we filled the entire roof frame with open cell foam right down to the bottom of the rafters, leaving no room for air.

So how do we like it? WE LOVE IT and it far exceeds what we expected. Why? 1st our small house is just that, small at about 500 total s.f. and we can heat it with a 1500W electric heater (decorative fireplace) no problem even in the middle of winter. 2nd It’s SO quiet inside it’s amazing. When we shut the windows it’s almost like we're in a sound-proof room.

So that’s it, our take on foam insulation. Look for the cost to keep coming down but even now still worth the investment in my opinion. 

Look for my comments soon on what's important to spend a few extra dollars on when building a home, which will include how to do foam insulation in a home with roof trusses.

Saturday, August 9, 2014

Pride in Workmanship

Well, we recently had some work done at our house. It always seems that when I call someone, it's hard to get dependable people. I find when I talk with others they tell me the same thing and I think this is way too common. They don't call you back, don't show up when they say they will, and if they do finally give you a quote, it's way over inflated. Worse yet if you question the price and they do come down a bit, they make sure you know it by giving you poor quality work. If you're too busy to do the job, just tell me right up front. Don't just give me a high quote and waste our time because you don't need the work.

Do any of these people expect to get more work or a good reference?

I know of and have known many good trades-people though, but it usually seems that these people aren't in the same position for long, they move up quickly succeeding in whatever they end up doing; replaced by, you guessed it, someone who really doesn't care about their work quality. Or at least not as much.

So which type of person are you and what do you care about? We all have some kind of job, whether service, or sales, maybe a bit of each. What do you think the people you serve say about you when they walk away?  I want people to say, "man that guy does a great job and really seems to care. He's reasonably priced too.

As a draftsman, home designer, and do-it-yourselfer, I care about my work quality and everyone I work for is a potential lifetime customer. It's the details that matter. I try very hard to look between the lines for what exactly will make the job go easier. In the case of home plans I think it's crucial that my customers have no problems with construction, that all the important details are there.

There are hundreds of home plan retailers out there but watch out, most of these are re-sellers, offering other peoples designs. I like to think if a customer gets a plan from me that it's me they call to get changes made. It's me that they talk to directly and It's me that cares about quality. Of course if you checked out our site, you've seen the pictures, and you know that almost all of our homes have already been built at least once. There will be no head-scratching questions when your builder is standing on the job site, we guarantee that.

See us at: www.completecad.com for a full range of Home plans, Custom Designs & CAD Detailing services.

Wednesday, August 21, 2013

What should be included in a quality set of house plans?



A Quality set of house plans from Complete Cad (CC) will include all 4 exterior Elevations noting Wall, Foundation and Truss bearing heights and exterior finish details where appropriate
All Floor Plans Including Foundation/ Lower Level finish, Main Floor and Second Floor plans where applicable
Wall Sections of each type; typically Foundation type, such as Full basement, Viewout, Daylight or Walkout and detail of any egress wells
At least One wall section detailing Foundation to Roof, typically required by Code officials for permitting
Typically at least one full section showing truss span and any unique features such as cathedral ceilings, porch overhangs and different wall heights for garages or porches where needed.
Stair Section noting all heights: Floor to Floor, Opening in floor, Guardrail, Railing, Head height as well as Tread and Riser sizes and any special details such as newel posts, custom spindle, enclosed or open tread details.
Any other details which would be needed to relate unique assemblies or designs to the builder such as custom porch columns, decorative gables, custom interior features such as cabinetry built-ins etc.

What about the actual prints? Typically you will need at least 6 -10 sets of prints to complete a residential home depending on how many subcontractors are involved. In many areas the building department requires 1-2 sets for the permit application. Foundation, Framing and mechanical sub-contractors should also have their own set. Many house plan retailers charge you, the plan purchaser, a substantial sum for each set of plans ordered. This can easily be hundreds of dollars. We think that's unfair and since we know you only plan on building one house, we email the actual PDF files directly to you. You can, or we can if you prefer, send them to a printer in your area and you can then print as many sets as you like. And since most printing companies charge by the square foot, this will save you money. Example: one printer in our area charges .30 - .70 per square foot.
Printing costs are your responsibility but there is no limit to the number of sets you can print. Note: each set of plans requires the building address on the title block and is only licensed for building at that address
If you are not aware of a printer capable of printing 24"x 36" in your area contact us and we can provide prints for you by mail for a per nominal fee.
Our typical print size is 24" x 36" with the usual set containing 5-8 sheets. A typical cost per square foot

Note: Complete Cad Inc does not provide structural detailing or design in any form. This is typical as lumber estimators will most structural elements based on local factors such as snow load, freeze index, wind, seismic and severe weather conditions. Lastly Foundation depths vary in different climate zones and will need to be adjusted. These adjustments as well as requirements for submittals of the additional documents will be noted on all plan sets. In most cases all the information to build is within the set, we only ask that any and all information is approved by local qualified structural engineers or estimators.