The words you are searching are inside this book. To get more targeted content, please make full-text search by clicking here.

GENERAL REPAIR GUIDELINES
RAISED FLOOR FOUNDATION SYSTEMS

Discover the best professional documents and content resources in AnyFlip Document Base.
Search
Published by Lineberger Consulting Engineers, Inc., 2018-02-10 21:23:18

GENERAL REPAIR GUIDELINES RAISED FLOOR FOUNDATION SYSTEMS

GENERAL REPAIR GUIDELINES
RAISED FLOOR FOUNDATION SYSTEMS

Keywords: REPAIR GUIDELINES RAISED FLOOR FOUNDATION SYSTEMS

LINEBERGER CONSULTING ENGINEERS, INC.

19141 Stone Oak Parkway, Suite 104 · San Antonio, Texas 78258
(San Antonio) 210-601-1379 (Austin) 512-522-9197 (Email): [email protected]

GENERAL REPAIR GUIDELINES
RAISED FLOOR FOUNDATION SYSTEMS

The following general guidelines & specifications may be used by the customer/owner/contractor when modifying, repairing, or
otherwise upgrading the existing Raised Floor Foundation system:

1. Where floor frame girders conflict with crawl space utilities or floor openings, girders my be offset by approved methods.
These methods shall assure floor joists are fully and safely supported within the area(s) of conflict.

2. Girder-to-girder ends shall be rigidly connected. Steel plates may be used as connectors. This includes girder end joints
located below interior floor framing/walls and exterior perimeter load bearing walls.

3. Any new foundation piers shall be minimum 10 inch diameter, shall be composed of minimum 2,500 psi concrete (28 day
yield), reinforced with deformed steel, plumb, and shall bear to a minimum of 2 feet depth below the ground surface. Any
existing cardboard pier forms may be left in place.

4. All foundation piers which support raised 4” x 8” floor girders shall be placed at maximum 5 foot on-center. 5. All main 4” x
8” floor girders shall be pressure treated and shall be fully supported by piers at their ends.

5. Girder-to-pier bearing surface contact shall not be less than 3.5 inches (supporting 4” wide girders).
6. Girders shall be fully supported by piers directly below load bearing exterior walls. Girders shall not “cantilever” below any

exterior load bearing wall.
7. All girders shall be rigidly fixed to their supporting piers below exterior load bearing walls. A minimum of two connectors

shall fix the girder to the concrete piers on either side of the supported girder. Go here for more information:
https://www.strongtie.com/columncapsforcmuandconcretepiers_masonryconnectors/ccqm-cctqm-ecclqm-
cccqmecclqmd_productgroup_wcc/p/ccqm.cctqm.ecclqm.cccqm.ecclqmd ) Other connector options may be available for
your specific application.
8. Approved underpins (new) shall be steel reinforced cylindrical concrete piers. Other underpin types such as cedar posts,
wood posts, dry stack CMU piers, or other temporary supports shall generally not be considered an acceptable permanent
underpin type.
9. Orphaned girders and piers shall be removed from the crawl space.
10. Should the customer increase dead and live loads by adding walls or other construction which bears atop the existing raised
floor, the customer shall assure these new-additional loads are adequately supported.
11. Crawl space access shall have at least two 24” wide by 16” height clear openings. Crawl space interior headroom clearances
from the ground surface to the bottom of the girder shall be minimum 12”. Crawl space interior headroom clearance from the
ground surface to the bottom of the joists shall be minimum 18”.
12. Assure crawl space ground surface slopes along the foundation perimeter drain or direct stormwater runoff away from the
crawl space and into an approved conveyance or outfall.
13. Crawl space ground surfaces shall be relatively smooth and free of trash or debris.
14. Customer may optionally place a vapor retarder atop the crawl space ground surfaces with the following characteristics: [a.]
permeance < 1.0 perm, [b.] conforms to ASTM E1745, [c.] minimum 6-mil (0.006 inch) polyethylene thickness or equal.
15. Assure placing a gridded and spaced system of steel reinforced cylindrical concrete underpins (piers) with a nominal 10” -
12” diameter bearing to a minimum of 24” - 36” below the crawl space ground floor surface. Grid spacing of the piers should
not exceed 5’- 0” on center along the residence perimeter and beneath or adjacent to load bearing interior walls. Refer to
http://anyflip.com/ajix/scph/ for general underpin (pier) detail examples.
16. Remove and replace any deteriorated structural floor frame girder or joist floor framing members with new structural
members. Refer to http://anyflip.com/ajix/scph/ for general wood floor framing examples. Assure any new interior or
exterior girders or built-up rim joists which support load bearing walls have the following characteristics: [a.] Wood Girders
(required for two story houses): minimum nominal 6” thick x 6” depth, treated lumber; [b.] Wood Girders (required for one
story houses): minimum nominal 4” thick x 6” depth, treated lumber; [c.] Wood Built-up Rim joists (required for two-story
houses): minimum (4) nominal 2” thick x 10” depth, treated lumber, lag screwed, bolted, or nailed together; [d.] Wood
girders or built-up rim joists shall be pressure treated; [e.] Wood girders or built-up rim joists shall be structural grade.
17. Assure any wood joists spanning load bearing residence walls are structural grade, minimum nominal 2” thick x 8” or 10”
depth spaced @ 16” on center minimum.
18. Assure reasonably level and flat residence interior floor surfaces. Maximum 1” elevation variation over a 25 foot span or less
than a 1% total floor tilt across the entire expanse of the foundation.
19. Pier-to-girder shims shall not exceed 1-1/2” in height. Shim materials shall be pressure treated wood products, steel, or
similar non-compressible, rigid/resilient water resistant material.

Page 1/2 LCE ERSC 2-2018

LINEBERGER CONSULTING ENGINEERS, INC.

19141 Stone Oak Parkway, Suite 104 · San Antonio, Texas 78258
(San Antonio) 210-601-1379 (Austin) 512-522-9197 (Email): [email protected]

20. Wood girders shall connect to their supporting underpins use permanent mechanical fasteners (other than nails) such as
approved metal anchors or connectors which adequately resist reasonably expected residential lateral, rotational, and uplift
loads.

21. Wood girders supported atop underpins shall rigidly connect to their adjacent girders at their end-joints using permanent
mechanical fasteners such as approved metal anchors or connectors, or interlocking end-notches. (End-joint connections
serve to resist reasonably expected shear and uplift loads).

22. The following Site stormwater drainage criteria may be considered by the customer:
[a.] any roof or ground surface stormwater should be drained to an existing or proposed underground collection system and
then subsequently discharged to an approved public conveyance (city stormwater drain or street).
[b.] all roof rain gutter downspouts should connect to existing or proposed subsurface stormwater collection systems.
[c.] ground surface drains/catch-basins may be added which directly connect to underground stormwater collection systems.

Page 2/2 LCE ERSC 2-2018


Click to View FlipBook Version
Previous Book
RAISED FLOOR FOUNDATION REPAIR GUIDELINES
Next Book
-Lisca Lingerie Catalog Spring Summer 2013