S2Kers: what can I do to further fortify my house?

[hesperhys]

Storm2kers... What can I do to further strengthen my house? Current vital stats:

Built in 1954

Thick CBS walls

Beefy barrel tile, hip-roof morphology

Roof joists 2x8/ 2x10 [unidentified dense softwood] joists, anchored every 32" by thick steel straps embedded in masonry wall. One-half-inch bolts with 1.5" washers tie down the top plates. (Interior roof joints are toe-nailed... points of weakness?)

Roof sheathing is 1x6 tongue-and-groove Dade Co. Pine.

Metal shutters (Semco steel & Rolladen Aluminum) -- post-Andrew Code -- for every window.

Suggestions for further improvement eagerly welcomed... I'm not really sure that "evacuation plans" here in Dade Co. take working folks into account... guess we're just expected to ride it out...

[edit for spaz on joist dimensions]

[shorrock]

Doors are a big area of interest. I remember reading somewhere that inward opening doors tend to fail easier then outward opening doors.

In addition, I've seen people conjecture (Never seen any Miami/Dade or WPB specs) for bolts on the top and bottom points of the door on opposite side of hinge.

My fear for our house is the door. I need to have a point of egress in case of emergency, so there has to be a door that can be "30 second" opened. Haven't found a good solution for this yet.

Have you checked the for the emergency operations center plans on evacuation and shelters in your area?

I would think you want to get the heck out of your house in that situation no mater what. If I remember the wind load tables, 110mph winds = 85psf load. figure the average side of a house is 20X10 = 200 sqft * 85psf = 17000 pounds of pressure (about 10 tons on that side, not including suction load on roof or existing weight of structre) keep that going up for higer storms. Don't know if i trust CBS construction that much.

[Ziplock48]

but one by's for joists?? I would definately add some 2" x 4" X 8' PT boards parralell to the walls, joining several trusses together. This adds a lot of strength, and if your roof IS breached, you will be less likely to have a domino effect where trussses fall like dominoes. Even though not a gable end, you may be able to brace the ends, which is always good.

Tiles did not fare too well in my neighborhood, but then again, shingles did poorly too...ANY missed nails in the roof covering was the beginning of the end for many roofs.

Remember, no one is going to go up there and look to see if the work you do is pretty to look at.

I have lots of extra bracing in mine....pre and post Andrew.

I am curious, since you have obviously thought this through...what have you done about your last point of ingress and egress? That is, if you shutter your whole house, you still need a door to get into the house....soooo, what about reinforcing that last door?

I feel like my front door, which faces north, is a weakness. Still need a way to get out in a hurry. Still need reinforcing. Right now, the only thing is the LOCK, which is nowhere near strong enough.

One comment...many folks think only of wind forces pushing (in) on surfaces. What many do not realize, is that the wind, when rushing across a surface, LOWERS the air pressure immendiately adjacent to the surface (Bernoulli effect). This must be kept in mind when preparing for a storm. shutters get sucked off the house, roofs get lifted up by this force. This is why flat roofs do poorly in hurricanes...like an airplane wing, there is more lift.

BTW, my nickname, Ziplock, refers to the fact that the only things I had left after Andrew were those things that had been put into Ziplock Bags.

Zip, I'm a great believer, obviously.

[hesperhys]

Yeah, I'm thinking about the doors, too... if we get caught here, would have a 12V battery-powered drill with 3" screws ready to tack the doors shut if winds look fierce...

I'm told these old houses were built to take 140 mph winds, but...

It's just too bad none of the local politicos would ever have the balls to invoke a true evacuation (e.g., all lanes of I-95 headed north, as provided by post-Andrew law). By the time an evac is issued, it's too late to get out of Dodge...

[hesperhys]

Oops... the joists are 2-bys... typo... they are at least two to three times the mass of the trusses we put up on houses I worked on in summers in Gainesville in the early '80s.

[edit: typos: it's getting late]

[hesperhys]

One thing I've read about is gluing the rafters to the roof sheathing with construction adhesive (e.g., liquid nails).

Kind of makes senses in that A) it should decrease the ability of the wind to strip the sheathing off of the trusses, and B) the new joints should help to resist the tendency for the roof joists to deform as members of a parallelogram in any given direction.

[Ziplock48]

I thought about using a liquid nails up there, but honestly, it is so hot and stuffy in my attic, I would need a respirator to apply even half a tube...the fumes are really toxic. For new construction, I'd say why not?

I have thought up some pretty crazy schemes for that extra touch of security...what if that extra bit of glue or oversized shutter bolt were the diffrence btw a house standing and total failure of roofs and walls?

The house next door to mine, built the same week as mine, in the early seventies, was completely GONE after Andrew...nothing but the slab. Microburst? Tornado? or just the wind eating a little bit here, nibbling a little bit there, then the wind gets inside, the roof lifts off...you know the rest of the drill.

I always took the "Three Little Pigs" story to heart. A strong house has a half a chance, a weak house has no chance.

Let's hope it doesn't come to that. It is too terrible to contemplate.
Cheers,
Zip