Home Improvement, Remodeling and Repair @ Builders Websource. Home design software, advice, tools, videos, tech notes, links and more!

Search: 

Home Page | Books | BuildersTALK | Building a Dream | Green Building | Links | Software | Tech Notes | Tools | Contact

Messages and Online Forum Q&A

If you find the answer to this question useful, kindly CLICK TO PAY here.



Knowledge


BuildersTALK
Building|Dream
Green Building
How-To Books
Links (Web)
Newsletter
Tech Notes
Videos

Software


BeamChek
Bidding
CAD | AutoCAD
Estimating
EZHomeBuild
Home Design
Landscaping
Lighting Design
PrioSoft
Resi-Cost
Structural

Specialty Tools


CrackMON
Tools
WatrLevel

Support & Info


About Us
Advertise
Contact Us
FAQ
Publish
Services
Support

 

Lift House for Basement

From: msrn04@comcast.net
Category: Foundations and Basements
Remote Name: 71.194.167.63
Date: 03 Jul 2006
Time: 12:08 PM

Question: I have a 2-story house on a 4' tall poured concrete crawlspace (floor & walls). I am wondering about lifting the house to extend the crawlspace walls up to an end result of a 8-9' high basement. Any comments, including pricing, on this idea would be appreciated.

Builders Websource Answer®: Converting your crawlspace into a basement may sound tempting at first. However, there are many factors to consider before you decide to proceed. Consider, for example that:

  • Most municipalities have strict height limitations as part of the local building codes. Will extending the height of the foundation walls by another 4-5 feet put the top of your house over the height limit? You already have a 2-story home, so check with your building official on any rules regarding maximum building height.
  • Adding to the top of an existing stem wall isn't easy structurally. Normally, you want the vertical rebar from the foundation to continue uninterrupted through to the top of the foundation wall, where it ties in to horizontal rebar along the way. While it is possible to make such an extension, you're likely to have a weak point at the seam, which will also be prone to moisture leakage. If you live in an area subject to earthquakes or high wind or snow loads, the structural integrity of the foundation is of paramount importance.
  • Your existing crawlspace probably wasn't designed with proper exterior drainage or waterproofing considerations. As a result, your basement could be subject to a continual water problem if you don't engineer a proper solution up front. Waterproofing basements are tricky enough even when built from scratch -- so you're depending heavily on the quality of engineering and workmanship to ensure that any "add on" after the fact is designed to account for moisture factors. Consider also that you may have to tear up landscaping and walkways to trench around your existing foundation in order to install moisture barriers and drainage.
  • Another factor is the actual cost. You could easily spend another $100,000 - $200,000 to extend your crawlspace into a basement, depending on the area. Depending on where you live, will this extra cost put your home's value out of balance with the rest of the neighborhood? If you plan to live in your house for a long time and really need the extra space -- adding a basement might still be cheaper than moving to a larger home. However, in many parts of the country, this added cost would be difficult to recover in the event you had to sell the home sooner than expected.

These are just a few of the many considerations you'll face in a project such as this, not to mention the cost of moving out while the construction work is underway. If you can justify the financial impact to your bank account, we urge you to consult with a highly reputable structural engineering firm to assist with the plans and provide project oversight during construction. When it comes to structural safety and waterproofing, cutting corners will only lead to an expensive disaster. Spend the money and do it right and you'll save in the long run.

 

Article Tools

BuildersTALK


Ask an Expert
Recent Questions
Click to Pay

Archives


2006-2007
Oct-Dec 2002
Jul-Sep 2002
Jan-Jun 2002
Jul-Dec 2001
Jan-Jun 2001
1999-2000

 

 


ASTM International