PHD Predeflected Holdowns / HDQ8 Holdowns

PHD holdowns are predeflected during the manufacturing process, virtually eliminating deflection under load due to material stretch. The unique seat design of the HDQ8 greatly minimizes deflection under load. Each holdown uses SDS screws, which install easily, reduce fastener slip, and provides a greater net section area of the post compared to bolts.

Special Features:

Wood screws reduce slip due to overdrilled bolt holes.
Smaller centerline reduces eccentricity in the stud.
No stud bolts to countersink.
Fits easily in a 2x4 stud wall.

Material: See table.

Finish: Galvanized. PHD2 and PHD5 available in hot-dip galvanized (HDG SDS screws included).

Installation:

Use all specified fasteners. See General Notes.
Place the PHD or HDQ8 over the anchor bolt.
HDQ8: 5/8" of adjustability perpendicular to the wall.
HDQ8: Use in vertical and horizontal applications.
Install Simpson's SDS 1/4"x3" wood screws, which are provided with the holdown. (Lag screws will not achieve the same load.)
For an improved connection, use a steel nylon locking nut or a thread adhesive on the anchor bolt. (No washer required.)
See SSTB Anchor Bolts for anchorage options. The Designer may specify any alternate anchorage calculated to resist the tension load for a specific job. Anchorage length should take the bearing plate/washer height into account, to ensure adequate length of threads to engage the nut. For 2-2x and 3x sill plates use SSTBL models.
To tie multiple 2x members together, the Designer must determine the fasteners required to join members to act as one unit without splitting the wood. See SDS Screw information.
SDS screws install best with a low speed high torque drill with a 3/8" hex head driver.
Refer to technical bulletin T-ANCHORSPEC for post-installed anchorage solutions.

For holdowns, per ASTM test standards, anchor bolt nut should be finger-tight plus 1/3 to 1/2 turn with a hand wrench, with consideration given to possible future wood shrinkage. Care should be taken to not over-torque the nut. Impact wrenches should not be used.

Allowable loads have been increased for earthquake or wind load durations with no further increase allowed; reduce where other load durations govern.
The designer must specify anchor bolt type, length and embedment. See the SB and SSTB Anchor Bolts.
Structural composite lumber columns have sides that show either the wide face or the edges of the lumber strands/veneers. Values in the tables reflect installation into the wide face.
Post design by Specifier. Allowable load values are based on a minimum wood member thickness in the direction of the fastener penetration. Posts may consist of multiple 2x members provided they are designed to act as one unit independently of the holdown fasteners. Holdowns shall be installed centered along the width of the attached post.
Tension values are valid for holdowns flush and raised off of sill plate.
Deflection at Highest Allowable Tension Load includes fastener slip, holdown elongation, and anchor bolt elongation (L = 5"). Additional elongation of anchor bolts longer than 5" shall be added to holdown deflection.
Tabulated loads may be doubled when the PHD or HDQ8 are installed on both sides of the wood member provided either the post is large enough or the holdowns are offset to eliminate screw interferences.
HDQ8 holdowns installed horizontally can achieve compression loads with the addition of a standard nut and square washer (BP7/8-2) below the holdown. Refer to ESR 2330 for design values. Design of anchorage rods for the compression force shall be per the Designer.
Allowable loads are based on criteria in ICC-ES AC155. Therefore, they are the lower of the strength determined from the test value on a wood jig divided by 3.0, the load at the AC155 deflection limit, and the fastener calculation based on the 2005 NDS.
Allowable loads are based on 3 1/2" wide post minimum.

					Legacy Reports
	IAPMO ES ER	ICC-ES ESR	CITY OF LOS ANGELES	STATE OF FLORIDA	ICC-ES NER	ICC-ES ER	ICC-ES ES
HDQ8-SDS3		ESR-2330	RR25540 / RR25720	FL1463		ER-5938
PHD	See specific model numbers for code listings.
PHD2-SDS3		ESR-2330	RR25720	FL503
PHD5-SDS3		ESR-2330	RR25720	FL503
PHD6-SDS3		ESR-2330	RR25720	FL503
PHD8-SDS3				FL503