Porch-Carport Uplift Calculator_ASCE 7-22

Last Updated 4/16/2024

FORTIFIED™ Home Uplift Calculator for Porch/Carport with Flat Roof^1,2,3,4,5,6

This calculator is limited for use by building professionals to determine required prescriptive retrofit uplift loads for attached structure connections in conjunction with Section 5.8 of the 2020 FORTIFIED Home Standard to achieve a Silver designation. The required uplift loads provided may be used only if the attached structure meets all eligibility requirements listed in Step 1.

Step 1: Confirm that the attached structure meets all of the following prescriptive eligibility requirements:

• Rectangular or square plan; 20'D (max.) x 25'W (max.) w/ up to 1.5' max. overhang

• Flat, monoslope roof

• Weight of roof = 7 psf minimum

• Mean roof height = 15 ft

• Framing geometry configured as shown in Figure 1

Step 2: Enter the following site information:

Design Wind Speed, V_ult =

mph

Exposure =

Porch Depth, D =

Porch Width, W =

Roof Member Spacing, S =

Overhang Length, OH =

Number of Columns, N =

Figure 1

Step 3: Record the required uplift capacities for each connection on the SC2 Silver Compliance Form for Contractor:

Required Uplift Load (ASD) for Connections:

Inside column to foundation:

lbs →

column base connector must have allowable uplift (lbs) of at least:

Inside column to beam:

lbs →

column cap connector must have allowable uplift (lbs) of at least:

Corner column to foundation:

lbs →

corner column base connector must have allowable uplift (lbs) of at least:

Corner column to beam:

lbs →

corner column cap connector must have allowable uplift (lbs) of at least:

Each roof member to beam:

lbs →

straps/hangers/ties must have allowable uplift (lbs) of at least:

Step 4:

Metal connectors (such as column bases, column caps, straps, hangers, ties) must have published allowable uplift loads that meet or exceeed the required loads from Step 3, and verify that connectors are installed per manufacturer installation instructions. Contact connector manufacturers for additional information and guidance in selecting appropriate connectors.

Notes:

1. For the purposes of this calculator and the FORTIFIED Home program, an "attached structure" is defined as an outdoor or

semi-outdoor space with a solid roof that is attached to an exterior wall or the roof structure of the main building.

2. Wind uplift design pressures used are per ASCE 7-22 section 30.5 and assume the following:

• Rectangular or square plan; 20'D (max.) x 25'W (max.) w/ up to 1.5' max. overhang

• Flat, monoslope roof

• Weight of roof = 7 psf minimum

• Mean roof height = 15 ft

• Framing geometry configured as shown in Figure 1

3. Required loads for connections provided are ASD.

4. The supporting foundation requires independent verification of adequacy for applied loads.

5. For conditions outside the limitations of this calculator, consult a professional engineer.

6. This design aid is intended to be preliminary guidance for use with the FORTIFIED Home program - Silver designation. Design must meet or exceed local code requirements. This aid does not supplant the need for drawings or plans to be reviewed and signed by a professional engineer.