Friday, August 13, 2010

They Don't Build Houses Like They Used To?

You've heard it.  You've probably even said it:  "They don't build houses like they used to."

Did you know that that's a DARN good thing?

I'm not talking about exotic tile floors, stained glass, fancy woodwork, and impossibly curvy stair railings.  I'm talking  the "BONES" of the house.  The foundation and the framing.

Ever see/smell a "rubble" foundation?  It's the ultimate "green" technology, green in that it's leaky/danky/stanky/moldy/mossy.  Made of stacked field stones and about two feet thick.  No more.  Now we use poured concrete, ICF [insulated concrete form] systems, concrete blocks, or some sort of precast product.  The rubble foundations support houses just fine.  We like that part.   But they leak, are in a continuous state of collapse, and are MISerable and expensive to stabilize when remodeling.

Old covered porch footings are a pet peeve of mine.  The footings under porch piers were routinely undersized, not excavated to below frost depth, and yet expected to support the loads from roof/snow, and often from more than one floor.  The result?  The too-small footing is slowly driven deeper into the earth, taking everything with it.  Prevention is easy.  Calculate the load in pounds, determine the soil bearing capacity in pounds/square foot, divide the former by the latter, and that's how many square feet of footing area you need.

Free-standing garages were often poured on an unreinforced slab.  No footings at all.  The edges of the slab cracked and tipped, gradually sank, and exposed the wood siding and framing to the earth, allowing it to rot.  Today we use a full frost depth footing, or a monolithic slab.  A monolithic slab is reinforced with steel, and has a thicker steel-reinforced edge.  Sort of like a raised edge cookie sheet turned upside down.

Often framing was either under-designed, or installed and then weakened.  2 x 6 roof rafters were used almost exclusively reGARDless of their span and spacing.  Floor joists under bearing walls were merely doubled when expected to carry loads from the floor above.  Porch floors were often trampoline-like.  Electrical conduit was installed in notches in the bottoms of joists, the WORST possible place, both by weakening joists immediately by reducing their effective depth, and by encouraging future cracks.  Floor joists were notched to bear on ledgers on basement beams, fostering cracks at the notches years later.

Carpenters had great skills using  handsaws, hammers, and chisels.  They had neither power tools nor attended training seminars.  "Construction" wasn't thought of as a science.  I've looked at houseplans of the era.  Even Architect-drawn plans for upscale homes didn't include many details.  The carpenters were expected to make it happen, and to the best of their abilities they did.  Fortunately for the carpenters and architects, balloon and platform framing, [the building of houses with "sticks" of lumber], is inherently "forgiving."  A lot of structural redundancy.  You can forget to add a stud here or there, or actually started removing pieces, and the house holds together.  It may waver, wiggle and sag, but it won't collapse.  We like that too.

Even today's simplest box of a home, no more sophisticated than an oversized birdhouse, has a structural design that has been thoroughly engineered.

Foundations are now designed out of stable materials, reinforced as required, made water-resistant, and equipped with proper drainage.

Framing is now sized from span/load tables in the Building Code. Pre-engineered trusses allow longer clearspans.  Joists, studs, rafters/trusses generally align in a modular fashion, allowing problem-free load flow from the roof to the foundation.  Fire-blocking is provided at all floors.  Engineered lumber can be used to created strong beams flush within a floor, to support loads from above.  Plywood or OSB sheets create stiff floors, walls, and roofs.  Joists are drilled instead of notched to allow wires and flexible plumbing to slip through.  If joists must be notched, they're cut within certain depth and distance guidelines.  Engineered steel hangers replace notching/ledgering.

In summary:

Those of yore who designed and built the floor, were not daft in the rafters.  They employed the accepted architectural and construction practices of the day, and used the tools and materials available.

But now we do it better.

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