Hybrid Gas Water Heater

The wife's been complaining about the limited hot water from our ancient (ca 1996) tank-type water heater.  In Japan, of course, they use tankless heaters, which is evinced by the major manufacturers being Japanese: Rinnai and Noritz.  Anyway, recently when talking with a builder-type dude, he mentioned hybrids as being the favored type now.  When I looked into it, most hybrids are electric, except for the Eternal GU120.  The size of the tank isn't clearly specified, but from one of the documents it's implied that it's 2 gallons.  $1400, with a $300 tax credit for 2013.

Trusses Again

Well, back to this.

To get the terminology, diagrams help.  The same site implies that sistering the bottom chord is sufficient to reduce sag: "Undersized bottom chords should be stiffened to prevent ceiling sag and cracking of ceiling finishes. Adding a second member to the bottom chord would normally be satisfactory."

A FH blog post had some conflicting advice.  The solution I thought was most sensible was in the comments: "run a beam under the joist,no post needed, create a beam pocket at one end with double 2x4 cripples and 2x12 double simpson hanger at overhead header. Use 2x12 and 1/2 plywood glued with PL400 and your done."  Except that's probably to reduce the span; my issue is that running something cross-wise isn't an option.  It could work for the shelving, perhaps.  I'd have to remove the drywall to install the trimmers for the beam pocket, though.

A JLC article suggested a composite beam along the lines of the above.  Sounds expensive.

Perhaps I should go find myself a structural engineer to bother regarding my problem.  Expertise ain't free.

Load Calculation

In lieu of a real structural engineering calculation, from various reading online, here's how I gather it's done.  In my application, I need to calculate the minimum number of jack/trimmer studs to support a 24 ft roof truss span with a 2 ft overhang to get a clear opening of 6 ft.  The load factors are the dead load of the roof weight itself and the projected roof snow load.  Live load is irrelevant since the snow load will exceed the live load requirements.  One concern is that I don't know what kind of wood was used in the construction of the house, so I need to determine that as well as the relative strength with respect to the wood specified in the tables.

The Southern Pine Council has some nice resources to calculate spans and such, of course using southern pine for framing.  The Headers and Beams document contains information to calculate the header needed for a given span, as well as the allowable roof load given a header and number of trimmers.  The latter is what I was looking for, and the illustration for the load calculation is quite helpful.  (This is the ref207.pdf file, numbered page 27, which is 29 of 36 in the PDF.)

eHow has an article on the calculation of roof snow load based on ground snow load and the pitch and area of the roof.  The article makes reference to a Cornell University snow load calculator, but doesn't provide a link.  A search turned up a course page with a calculator.  (Perhaps I should buy the textbook, Structural Elements for Architects and Builders, by Jonathan Ochshorn.)

The other concern is wind load, since we get a lot of wind on the hill.  The IRC has something to say about that, which I have yet to research.

Of course I'd feel more comfortable having a professional do the calculation; the conundrum being, am I neglecting my due diligence if I don't?

Thoughts on Building a Vault

This turned up in my framing search, which I thought was amusing.  Arfcom has the most out-there posts.

Framing Code

I've been looking for guidelines on framing of a 6' rough opening.  A couple contractors I've talked with seem to think it's ok to widen a 5' 10" rough opening by either removing one trimmer/jack stud 2x4 on either side, and replacing it with a 1x4 board.  According to the International Residential Code (IRC 2009), for a ground snow load of 50 psf, which is specified by Minnesota State Building Code, regardless of the building width, at least two jack studs are required for each end.

The free online IRC isn't searchable, so the code finder from This Old House is useful.

This is problematic.  Perhaps I should consult a structural engineer regarding the engineering margin.

Beam Deflection

Needing to reinforce the structure of my garage attic to support increased load, I'm trying to figure out what kind of member it needs to be and how big to support the relatively long span with minimal deflection. Since the span needs to be about 20 feet, I'm thinking it has to be a box beam, since that would allow for the use of shorter lumber in its construction.

Wikipedia has an entry for deflection so that this can be calculated, but I need to figure out the modulus of elasticity (E) and the area moment of inertia (I). I'd better do some more studying.

For regular joists, I found a calculator for maximum span as well.

Range/Dryer Power Cords

It's a long story, but I found occasion to need to change the power cord from a 3-prong plug (NEMA 10) to a 4-prong plug (NEMA 14).  There's a useful howto online that clearly describes the process.  Following these instructions, the switchout went off without a hitch.  The GE-made 40A cord cost $20 + tax at Home Depot, though!

Shutters

Ever since seeing the security shutters that shops in Japan use, I've been interested in security shutters for windows at my house.  One of the roofing companies I checked out had photos on their web site of a window with real shutters, not the lame vestigal ones used on most houses these days.  That prompted me to see what I could find, and a search turned up a site with a bunch of links to various manufacturers.

Living in the upper Midwest, obviously I'm not going to have issues with hurricanes, but the functionality is similar.  One manufacturer's site that I checked, QMI, had pretty much what I was looking for.  Unfortunately, no prices are listed.

This sort of thing would be good to have for SHTF scenarios, at least for one's first floor windows.  They won't stop bullets, but it'd at least protect one of the weaker access points in the home, buying time to repel the invaders.

FH Workbench Designs

• Folding workbench
• Modular workbench
• 4 knockdown designs

The Sagulator

The Sagulator is an interesting calculator that will compute the deflection of shelves depending on the load, material, and dimensions.

Glass Blocks

I was considering making a glass block skylight, so I did a little search and found that a company IBP (Innovative Building Products) makes them. It wasn't quite what I was looking for, but amusingly enough, IBP is a Berkshire Hathaway company.

IBP also makes glass walkways and such, which is kinda cool, too.

Pittsburgh Corning actually makes glass blocks—the IBP skylights are a derivative product. They have a projects site as well. According to IBP's site, other vendors include Solaris, Mulia, and Weck.

Insulation

Searching for the foam insulation my neighbor was using under the siding she replaced (unfortunately I forgot the name), I came across a Dow site on various building materials. They have a number of foam insulation products for various purposes. Home improvement has a lot of choices to consider, especially in the area of materials.

Cultured Stone

In the Think Bank "Swap & Shop" there was a post advertising "River rock cultured stone". I wasn't sure if this was a brand or not, but a quick search turned up an Owens Corning company called Cultured Stone. They make the River Rock type of "stone veneer". I rather like the ledgestone designs.

DRIcore

Daren was installing this DRIcore subfloor in his basement. Sounds like a great idea. The only problem is the impact on ceiling height, compounded by the necessity for any in-floor heating to go on top of the subfloor. However, this is probably a necessity for having flooring in the basement.