Building Codes for Decks: Essential Guidelines for Safe Construction

As a con­trac­tor, your cus­tomers rely on you to deliv­er a deck that’s beau­ti­ful, func­tion­al and secure. While build­ing an out­door deck may seem like a sim­ple project, there are build­ing codes that must be fol­lowed to ensure the safe­ty and dura­bil­i­ty of the structure. 

While build­ing codes may some­times seem like a has­sle, the structure’s safe­ty should always come first. 

Explor­ing and under­stand­ing the break­down of essen­tial safe­ty guide­lines for deck con­struc­tion will help ensure your deck project stands strong and sta­ble for years to come.

Key Building Codes for Decks

Build­ing codes for decks exist for sev­er­al key rea­sons, such as ensur­ing cor­rect load-bear­ing, ver­i­fy­ing the deck is prop­er­ly attached to a home and con­firm­ing that rail­ings and stairs are safe. 

Structural Integrity Requirements

Struc­tur­al integri­ty require­ments were cre­at­ed to ensure that every com­po­nent of a deck works to make a deck safe. It needs to be proven sta­ble, secure and able to with­stand both grav­i­ty loads and lat­er­al loads. 

The Inter­na­tion­al Res­i­den­tial Code (IRC) struc­tur­al integri­ty codes, pub­lished by the ICC, guide con­trac­tors on:

• Foot­ings and Foundations 
• Posts 
• Beams and Girders
• Joists 
• Ledger Con­nec­tions 
• Lat­er­al Load Connections 
• Guards and Railings 
• Stairs and Handrails 
• Fas­ten­ers and Connectors 

Local build­ing codes may have fur­ther strin­gent require­ments based on the local climate.

Material Specifications

The IRC also cov­ers mate­r­i­al spec­i­fi­ca­tions because a deck built with unreg­u­lat­ed mate­ri­als can fail due to rust, split­ting, break­age or oth­er dam­age. These spec­i­fi­ca­tions include:

Lumber Specifications

• Pres­sure-Treat­ed Wood: Any wood that will be exposed to the weath­er must be pres­sure-treat­ed or nat­u­ral­ly decay-resis­tant (like cedar or redwood).
• Ground-Con­tact Rat­ed: Posts and beams that are in con­tact with the ground or embed­ded in con­crete must be rat­ed for ground contact.
• Grades: Struc­tur­al fram­ing such as joists, beams and posts must be grad­ed lum­ber that’s suit­able for struc­tur­al use, usu­al­ly No. 2 or better.
• Species Mat­ters: Dif­fer­ent woods have dif­fer­ent strength properties.

Fasteners and Connectors

• Cor­ro­sion Resis­tance: Fas­ten­ers and met­al con­nec­tors must be hot-dipped gal­va­nized, stain­less steel or made from oth­er cor­ro­sion-resis­tant materials.
• Pro­hib­it­ed Fas­ten­ers: Alu­minum fas­ten­ers shouldn’t be used with treat­ed wood because of chem­i­cal reac­tions that cause corrosion.
• Mechan­i­cal Con­nec­tors: Struc­tur­al con­nec­tions (like joist-to-beam or post-to-beam) require approved con­nec­tors like joist hang­ers, post caps and bolts.

Flashing

Ledger flash­ing must be made of approved cor­ro­sion-resis­tant mate­r­i­al like cop­per, lead-coat­ed cop­per, gal­va­nized steel or vinyl.

Guard and Handrail Materials

Guard posts, balus­ters and rail­ings must be made from decay-resis­tant mate­r­i­al or pro­tect­ed from weath­er expo­sure. Guards must be capa­ble of resist­ing a 200-pound con­cen­trat­ed load applied at any point on the top rail.

Plastic/​Composite Decking

Com­pos­ite or plas­tic deck boards must be approved by a build­ing code offi­cial and installed per the man­u­fac­tur­er’s instructions. 

Concrete

Foot­ings must use con­crete with a min­i­mum com­pres­sive strength of 2,500 psi unless oth­er­wise required by local codes.

Load-Bearing Capacity Standards

The load-bear­ing capac­i­ty stan­dards for res­i­den­tial decks are found in Sec­tions R301 and R507 of the IRC. They are a base­line, and local require­ments may vary. 

• Live Load: The min­i­mum required live load for a deck is 40 pounds per square foot. This accom­mo­dates the load for peo­ple, fur­ni­ture, and grills. 
• Dead Load: The typ­i­cal assumed dead load for a deck is 10 psf. That accounts for the weight of the actu­al deck mate­ri­als like deck­ing, joists and rail­ings, plus more per­ma­nent struc­tures like fire pits and hot tubs.
• Snow Load: Snow load require­ments vary by location.
• Guard Load: The con­cen­trat­ed load on guardrails must resist 200 pounds applied in any direc­tion at any point along the top. 
• Stair Load: Stairs must sup­port a live load of 40 psf, like the rest of the deck.
• Con­cen­trat­ed Load for Struc­tur­al Mem­bers: Joists, beams and ledger con­nec­tions must be capa­ble of han­dling con­cen­trat­ed loads in addi­tion to dis­trib­uted live and dead loads.

Avoid Common Code Violations

Many loca­tions require per­mits to con­firm that addi­tion­al struc­tures meet local reg­u­la­tions. Typ­i­cal­ly, per­mits must be obtained from local author­i­ties after all reg­u­la­tions have been sub­mit­ted for review.

Researching Local Codes & Obtaining Permits

To find out what local build­ing code reg­u­la­tions gov­ern deck instal­la­tion in your area, you should first con­tact the local build­ing depart­ment or per­mit office. Be aware that it can take time to get the nec­es­sary per­mits, espe­cial­ly dur­ing the spring when deck projects are most popular.

Common Variations by Region

Region­al vari­a­tions in build­ing reg­u­la­tions are gen­er­al­ly relat­ed to weath­er or envi­ron­men­tal risks, like:

• Frost Depth Requirements 
• Snow Load Requirements
• Wind Load Requirements
• Seis­mic Requirements
• Wild­fire Regulations
• Local Aes­thet­ic or His­toric Dis­trict Requirements

Building Codes for Decks: Safety Features

Decks are always required to have safe­ty fea­tures in place. These include:

Guardrails and Handrails

Guardrails and handrails on decks pre­vent falls and pro­vide secure hand­holds on stairs. They’re required to be strong enough to han­dle con­cen­trat­ed loads.

Stairway Regulations

Stair­way reg­u­la­tions low­er the chance that some­one will fall or that the stairs will fail over time. Reg­u­la­tions for stan­dard tread depth, ris­er height and handrail place­ment cre­ate safer access to and from the deck.

Weatherproofing and Drainage

Reg­u­la­tions for weath­er­proof­ing and drainage pro­tect both the deck struc­ture and the attached build­ing from mois­ture dam­age. Prop­er flash­ing, drainage gaps and water-shed­ding pre­vent rot, cor­ro­sion and struc­tur­al fail­ure over time. 

Build Safe Decks With Reliable Solutions from FastenMaster

When it comes to cre­at­ing a safe and secure deck for your cus­tomers, you need fas­ten­ers you can depend on. 

Look no fur­ther than FastenMaster’s Deck Solu­tions, where you’re sure to find the lat­est code-com­pli­ant fas­ten­ing solu­tions for your deck­ing project.

With Fas­ten­Mas­ter, you can trust that your deck­ing job will look beau­ti­ful and stay strong for years to come. Find out where to buy prod­ucts near you to get start­ed on your deck project today.