Subscribe or Renew Membership Subscribe Renew

Question on "soil nailing" costs ..

newbuilder's picture

Question on "soil nailing" costs .. (post #215535)

Anyone here familiar with a process called 'Soil Nailing'???

We've been in our house in a residential neighborhood of South Seattle for 25 years.  Our site shares a 100 foot property line with an extra large lot that's sceduled to have a large apartment building with ground flr commercial built on it.  The builders are wanting QUITE a bit of open access along that entire 100 foot edge of our property, including a year of total access by all kinds of heavy equipment, with scaffolding up against the length of our house, removing some things and replacing them later, and other 'allowances' on our part. 

One fo the things they want to do is "SOIL NAILING" into our property and under our house.  It has to do with excavating their property, and then creating underground parking with cement walls that will be braced during construction by the long re-bar "nails" penetrating our yard. 

Our 100 feet will be just one section of something like 500 to 600 feet they'll be doing ringing the excavation. We are, of course, wondering 'how much will our allowing Soil Nailing be saving them in costs?'.(If we said 'no', of course they'd be forced to keep everything on their side of the line). They absolutely stonewall us on any suggestion of curiosity on our part.  We are at this point thinking that we will allow them to go ahead with their needs, but we are still very curious as to how much we are 'helping out' on this near 30 Million dollar (really) project. 

Anyone got a clue about some sort of 'ballpark figure' on how much we'll be helping out? 


Pretty much impossible to say (post #215535, reply #1 of 11)

Pretty much impossible to say without detailed plans.  Your permission could be the difference between the project being feasilbe or not.

Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

"What's in it for me?" (post #215535, reply #2 of 11)

That's the most important question you can ask when somebody needs something from you. Don't give anything away for free!

+1 OP never did say what (post #215535, reply #3 of 11)


OP never did say what his compensaton was to be, in Seattle area, should be at least mid to high 5 figures. 

Heck, even way down in Renton suburb, I got $4k just for allowing a soil boring. . 

Whatever they offer first, triple your counter offer. 


Of course, they may just ignore you out of spite then.    And talk to your other neighbors to be sure! 

You can always offer to sell your property to them for above market value also. 

They are asking for complete (post #215535, reply #4 of 11)

They are asking for complete access along the 100 ft boundary extendign 12 into the property .. which is a little weird because our house is only 7 or 8 feet away from the line.  Right now they are offering $500 month .. which a noted architect friend of mine described as "That is completely absurd - a rip-off!  They are trying to take advantage of you".  An attorney that I spoke to briefly said "DON'T just give it away for free!"  But the thing is, I can't even get a hazy ballpark figure on how much we might be saving them!  Not even HERE!  ;)   

And by the way they have asked and asked if they could buy our house, but they are VERY DEFINITELY low-balling us on the price, and when I called them out on it they insist that it is "only worth what the ground it worth to build on".  Which is crazy of them because we could sell it for 200K more than their offer in about 3 days if we wanted to. 

If we don't 'comply' with their request they will have to pull their project BACK from the line so that they can do their work while remaining solely on their property .. they will therefor need at LEAST a few feet of there property that is not covered so they can work off of it. This would result in our not being so 'squished in' in the long run.  And it would cost them at least 300 to 400 square feet of built space.  

But, again, we could be saving them only 40K ... or we could be saving them 400K !  If we are saving them a few hundred thousand PLUS we really won't be able to live in our home for at least a year, then their $500 a month is, indeed, absurd and an insult.  What we really need to know at this point is .. how much is allowing them to quickly and easily soil nail under our property, instead of supporting the wall from within their own property only, going to benefit them? 

Sure would appreciate anyone who has any legitimate sense of it at all shooting us some info on it!  

Thanks again -

The problem is you are asked (post #215535, reply #5 of 11)

The problem is you are asked my a heavy commercial construction question on a homebuilding site... you may get some answer but you have no clue if it’s good or not.  If you already know an architect, then offer him a couple of hundred dollars to have a consultation with you over lunch or dinner that you will pay for.


if it were me, and I really wanted to stay, I would be putting together a reasonable sale price for the home (not an iv got you over a barrel price).  I would go to them with said price and tell them you will sell as long as they give you a life estate in the property.


A life estate means you get to live in the property for the rest of your or your spouses life whichever comes last.  Tell them this is their only option other than staying on their own property... and let them know you will be video taping the entire build and you will report every thing you think is a code or safety will put osha on speed dial along with ICE.  If they so much as start one minute prior to city ordinance or stay one minute late without a specific waiver from the city, you will report it including every truck that double parks waiting to get on the site.  In other words, let them know you can be their best friend if they buy your house or their worst enemy.

12 ft by 100 foot = 1,200 sq (post #215535, reply #6 of 11)

12 ft by 100 foot = 1,200 sq feet.  -  about how far they would have to pull back per what you said. 

I'm bettinghta they would put soil naoil all the way up to your foundation wall, however far that is, more thatn 1200 sq ft.   .

Check witht he city building depts, has any permit been issued yet?  If so, you may hae them over a bbl somewhat.   Look at what permits have been posted or granted. 

Out here in the burbs land cost is about $400K an acre now in a decent location.   (1200/40000)*400K is $12,000 cost to them in land cost. 

$500 a month is a ripoff for sure.  What is the time estimate, when does it start, etc.  9 months at $500 is only $4500. 

Hold out for at least $9K, your breathing space (that extra 12 ft barrier space) is worth more than that though, so just tell them to take a hike? 

From  one soil handbook, soil nailing costs are about $80 sw foot (NOT surface are, the 100 ft by the depths, say yours is for 40 ft deep for 2 level UG parking garage) is about $80 per sq ft so their foundation soil nailing costs along your property are about 40*100*80 = $320K!!

Did they tell you that the soil nails will deposit a big chunk of grout into the soil that is permanent?  How will that effect the future value of you land? 

I looked at one San Diego soil nailing estimate for an excavation for a road (a permanent soil nailing) and that was $320 a square foot!  1500 sq feet, $525K.  ref: Torrey pines road estimate. 

Good luck.  The folks you are likely dealing with make their living lowballing folks.  

Personal opinion:  I'd tell them, "since you are decreasing my potential enjoyment of my property, I see no reason to do any deal with you other than to sell all at slightly above fair market value"  Which is extraordinarily HIGH in Seattle right now. 

I'd even add on " and to me fair market value is what it would cost me to buy a similar house nearby and move" 

PS:  A neighbor just on lot (post #215535, reply #7 of 11)

PS:  A neighbor just on lot north of me here sold his 8 acrce and developer put 62 house on it!

They wanted to add a road between our houses.  One of the neighbors read chapter and verse of all the county codes and ordinances and stopper the road - had to reroute it onto existing county right of way. The particualr developer (via big campaign 'contribution')  somhow got the zoning changed from R-4 to R-8, everything else in area still R-4. 

I despise most large developers - there are however still a few decent ones aroung, but the mega millions  to be made in Seattle area seem to corrupt a lot of people.

A 9 acre 1/2 mile from me was nicely done with only 30 some houses.

Use of your property. (post #215535, reply #8 of 11)

I would think that if they "nail" under your property you will never be able to build anything new on it.

No you shoul dbe okay in the (post #215535, reply #10 of 11)

No you should be okay in the future. The nailing is a temporary support of excavation (SOE) to allow four construction of the foundations. Once you backfill it serves no purpose.

There is a question as to (post #215535, reply #11 of 11)

There is a question as to whether it will cause subsidence or other problems on the property.  They should, of course, warranty against that somehow, but it's hard to say how much you can trust their assurances, even if written.

Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

Thank you all very much for (post #215535, reply #9 of 11)

Thank you all very much for taking the time and trouble to respond!!  I really appreciate it.  I've got to cook on this whole thing and try to formulate a clear path forward. 
If anyone has anything further to say (or to ask) please don't hesitate and I'll respond as quickly as I can. 
Thanks again!