Seismic retrofit cost

South Bay
1

Anyone here done a seismic retrofit to their house? How much did it cost? Do you have any contractor recommendations. I have a 1400 sq ft house in San jose built in 1962. It is bolted to the perimeter foundation. Got an internet quote of $10k ---- seems a bit steep.

2

What does it include ??? new shear walls and hold downs… Seismic analysis??? Or just stock bolts and clips?

3

From their website they will

  1. Calculate weight of house
  2. Use Base Shears formula to determine number of anchors
  3. Use two types of anchors
    a) foundation anchors to tie the foundation to the mud sill ( these cost @ $200 per anchor)
    b) shear transfer ties to attach the mudsill to the floor joist

Again house has no cripple wall - joist rest directly on perimeter foundation. Anything else I should consider - thanks in advance?

4

This might be the wrong advice for some, but I always go with the motto “if it ain’t broken, don’t fix it” when it comes to real estate…

1 Like
5

Not a real seismic retrofit… Just anchor bolts for $10k
No way save your money fugetaboutit

6

@Elt1
Resurrecting and old thread…

A recent inspection by the foundation contractors discovered that our house doesn’t have a foundation anchorage. Here’s their comment:

Their proposed work items are:

  • Install Shear Plates at 6’ Spacing
  • Install A35 Clips at Sill to Rim Joist/Floor Diaphragm
  • Install Blocks at Parallel Joist Framing, Install FJA Uplift Straps at +/-6’ Spacing

Overall, would cost ~$20k.

Is this a necessary work? I called in for another inspection from another company and they did not recommend this at all. I wonder if this is a new recommended thing that was never required for older homes (the home is built in 60s), and many owners just live happily.

7

Anchor bolts have been required since 1940. Past standard was 1/2” bolts at 6’
Now 5/8 at 4’ oc.
Hard to believe you don’t have bolts. Clips and such may be needed. Better to consult with an engineer before shelling out $20k

8

Thanks. Its not clear if someone overlooked it since the inspection was done as part of a sale of the home…

9

You can crawl under and verify the bolts