Typical cost in Seattle
FEMA P-1100 states that using its provisions is not intended to prevent damage, and nothing here makes a house earthquake-proof. What Seattle Top Foundation Repair does is address known weak points: bolting the frame to the foundation and bracing the short walls below the first floor.
The service covers Seattle, Bryn Mawr-Skyway and White Center. Seattle has its own retrofit planset for homeowners, described below, and about 30 percent of the city’s homes predate 1950, so finding out what a crawlspace already has comes first.
SDCI’s retrofit guide organizes its plansets around three letters, and anchoring is the first: attaching the house to its foundation. A house that is not attached can jump off it during an earthquake, which is one of the two main sources of damage the guide names.
Bracing comes second. The short wall under the first floor, called a cripple wall or pony wall, can collapse, which the guide gives as the other main source of damage. Plywood sheathing nailed to that wall is one way to stiffen it.
Connecting is the third letter: tying that short wall to the floor it holds up. Where connectors go, and which ones, come from the plan for the house and not from a rule of thumb.
Seattle has adopted a prescriptive planset for residential seismic retrofits, produced with FEMA and the Seattle Office of Emergency Management. SDCI says it helps qualifying owners obtain permits sooner and spares them hiring a design professional for the drawings. Tables in it show how much of the outside wall below the first floor must be braced and how often it must be anchored to the foundation and first floor.
Applications go through the Seattle Services Portal, and a voluntary retrofit that uses SDCI’s PROJECT IMPACT planset pays a reduced fee. The planset is something the city offers homeowners; whether it fits your house depends on the checklist inside it.
SDCI’s criteria for the prescriptive planset are light wood-frame construction with a light roof, a regular shape, a concrete or reinforced masonry foundation in good condition, a height of up to three stories depending on the support wall below the first floor, and a relatively level lot. The checklist in the planset has to be completed and submitted to SDCI.
A house outside those limits can still be retrofitted, but SDCI says an architect or structural engineer must prepare the plans and review may take longer. Check the foundation’s condition first, since a cracked or settled one is a separate job, and foundation settlement and piering covers that.
Go into the crawlspace, or send someone, and check two things: whether anchor bolts pass through the sill plate into the concrete, and whether the short walls are covered in plywood. A photograph along the line where framing meets foundation shows both.
Damp or soft sill wood has to be repaired before bolting, which crawlspace post and beam repair describes.
On the Applied Technology Council’s store page, FEMA P-1100 is described as a method for assessing and retrofitting known vulnerabilities in wood-frame homes for one or two families, with provisions expected to improve earthquake performance but not intended to prevent damage. An undamaged house is therefore not something we promise.
The price of a retrofit follows the house, so the crawlspace is inspected before a written estimate is given. The drivers:
Wall length to anchor, short walls to brace, crawlspace access, damaged wood and any drawings all move the figure. We see the crawlspace before writing an estimate.
SDCI presents the planset as a way to obtain the building permits a retrofit needs, with plans submitted through the Seattle Services Portal. Ask SDCI about your house.
Anchoring and bracing the wall below the floor is about houses on crawlspaces. A slab house raises other questions; the visit establishes which apply.
Check the sill before the bolts. Rot there sends you to crawlspace post and beam repair, and the water behind it to foundation drainage; the home page has the other services.
Age of the house, presence of a crawlspace, bolts along the foundation wall: we would like to know all three. We'll get back to you soon with an estimate or any questions we have. Estimates are free and there's no obligation.
Call (206) 717-8636