AHEP Design Calculator

Design Input

AHEP Design

Select the type of material for the trusses (cold-formed steel or metal plate connected wood trusses).

Application

Select the desired design deflection limit of the AHEP equal to either L/180 or 3/16" (note a selection of L/180 is more conservative).

Deflection Limit

Select if there will be sheathing with a minimum thickness of 15/32" attached directly over the AHEP parts.

Sheathing

Roof Data

Input the hip end pitch in decimal format in inches per foot of run (i.e. 7¼ on 12 would be input as 7.25). Value must exceed 0.

Hip-End Pitch

/12

Input the desired on-center spacing of the AHEP parts.

AHEP Spacing

in o.c.

Input the on-center spacing of the trusses that are supporting the AHEP parts; not to exceed 24".

Truss Spacing

in o.c.

Load Data

Input the actual calculated dead loads of the roofing materials or as specified in the contract documents. Value must exceed 0.

Dead Load

psf

Input the controlling live load from the Building Code or the project contract documents. Value must exceed 0.

Live Load

psf

Calculation Results

This value is the calculated demand load that the AHEP is being asked to support based on your input span, spacing, live and dead loads. The dead load is calculated on the sloping length and the live load is calculated on the horizontal projection.

Total Down Load

lbs

This is the maximum load that the AHEP will support at your given span, spacing, sheathing, load and deflection criteria.

AHEP Allowable Load

lbs


	This is the length that the AHEP needs to be extended to and affixed with four (4) #10 self-drilling tapping screws. AHEP Part Length in. Length (L) that the AHEP needs to be extended to span between the trusses based on these input values.

General Notes to the Designer:

The AHEP is designed to perform as a structural purlin between 3/12 and 9/12 pitches.
The AHEP can be utilized as an installation lateral restraint and spacing aid from 3/12 to 12/12.
The AHEP part length (L) is from leading edge to leading edge of the framing members.
Minimum AHEP Lengths: At 3/12 pitch the AHEP minimum length is 21". At 4/12 and higher pitches the minimum length is 19 3/4". Straight line interpolation is allowed between 3/12 and 4/12 pitch.
Maximum AHEP Length: 30" when used as a structural purlin and 34" when used as an installation restraint and spacing aid only.
The calculator is doing straight line interpolation of Simpson Strong-Tie's published design values for the AHEP.
Demand loads are based on the tributary area determined from input values with the live loads calculated on the horizontal projection and dead loads on the actual sloping length.

General Notes to the Installer:

Product performance is dependent on proper installation described as follows:

Prior to installation, the AHEP must be set to the proper length and the two tubes fastened together with four #10x3/4" self-drilling screws through the round holes in the side flanges for pitches between 3/12 and 9/12; and in the triangular and upper round hole when the AHEP will be used as an installation restraint and spacer at pitches >9/12 up to 12/12.
For trusses spaced 24" o.c., the pitch markings on the inner tube may be used to line up the tubes to the correct length for a given pitch.
For other spacings, the length (L) of the AHEP must be set to the calculated sloping length (from leading edge to leading edge of the framing members).
To install the AHEPs on wood trusses, use four (4) 10d (.148"x3") nails. The two nails at the bottom of the part (the yoke end) must be clinched.
To install the AHEPs on CFS trusses, use four (4) #10x3/4" self drilling screws.
Sheathing is attached to the AHEP with knurled pneumatic fasteners or low-profile-head, self-drilling screws.
Refer to the current Wood Construction Connectors Catalog or Cold-Formed Steel Connectors Catalog for additional information.