Don’t Risk Your Life! How to attach deck roof support posts

Al-Shaan

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How to attach deck roof support posts

A good attachment of deck roof support allows you to get sturdy support against the weight of the roof. It provides a strong foundation for the entire deck. But how to attach deck roof support posts? Which deck post to pick?

Well, the process is easy. You need to determine the location of the post, prepare the deck surface, and drill the post hole. Then simply pour concrete, secure the post base, install the post bracket, attach the beam, add additional support if necessary, and finish the installation.

I know the process seems overwhelming. But trust me; it is not. With proper guidance, you can easily get the job done. We will guide you through the entire process. Hold up tight.


6×6 vs 4×4 deck post – which one should you use for roof support? 

In the war of 6×6 vs 4×4 deck post, the 6×6 post wins with its little more long-term stability. Along with performing better when carrying heavier loads, it also makes the heading for your roof more secure.

A 6×6 deck post measures 5-½  inches by 5-½ inches, while a 4×4 post measures 3-½  inches by 3-½  inches. The larger size of the 6×6 post provides greater strength and stability for generating ideal support for a roof.

Post SizeDimensionsMaximum Load CapacityRecommended Spacing
6×65-½” x 5-½”Up to 20,000 lbs6 ft
4×43-½” x 3-½”Up to 5,000 lbs8 ft

In fact, the International Residential Code (IRC) requires 6×6 posts for any deck higher than 6 feet off the ground. So I will suggest going with the 6×6.

But, a 4×4 post may be suitable for various purposes like smaller roofs or in situations where the roof load is minimal. 

According to the American Wood Council, a 4×4 post can support a maximum of 5,000 pounds, while a 6×6 post can support up to 20,000 pounds.

Another factor to consider when choosing between a 6×6 and 4×4 post for roof support is the spacing between the posts. The IRC requires 6×6 posts to be spaced no more than 6 feet apart, while 4×4 posts can be spaced up to 8 feet apart. 


Steps on How to attach deck roof support posts by yourself

Attaching deck roof support posts is like rocket science if you’re not clearly aware of every step. Here you get your idea clear.

If you are doing it with the new deck roof.

Step 1: Determine the height of the support posts

The height of the support posts will depend on the height of your roof and the clearance you need under it. Check your local building codes for minimum and maximum height requirements. Go for 6×6 or 4×4 deck post, depending on your needs.

Step 2: Measure and mark the location of the support posts

Use a measuring tape and a pencil to mark the exact location of the support posts on your deck. The posts should be evenly spaced and aligned with the roof’s structure.

  1. Start by measuring the length and width of your deck. You can use the dimensions of your roof structure as a guide to determine the spacing and placement of the support posts.
  2. Use a pencil to mark the exact location of each support post on the deck surface. Ensure the posts are evenly spaced and aligned with the roof’s structure.
  3. Take a level to ensure that the marks are straight and level. This will ensure that the support posts are vertical and properly aligned with the roof’s structure.

Step 3: Cut the support posts to the desired length

Using a saw, cut the support posts to the desired length. Measure twice and cut once to ensure the posts are the correct height. Use a miter saw or circular saw to make the cuts.

Step 4: Prepare the post anchor brackets

Attach the post anchor brackets to the bottom of the support posts using screws or bolts. Use 24” high 1/2” U-shaped steel brackets. These brackets will secure the posts to the deck and prevent them from shifting.

Step 5: Install the post anchor brackets onto the deck

Attach the post anchor brackets onto the deck using lag bolts or other recommended hardware for your specific deck structure. Ensure that the brackets are properly aligned and level with each other.

Step 6: Secure the support posts to the anchor brackets

Once the brackets are secured to the deck, insert the support posts into the brackets and fasten them with screws or bolts. Ensure that the posts are vertical and level with each other.

Step 7: Add additional support if necessary

If your roof is particularly heavy or if you live in an area with high winds or heavy snow loads, you may need to add additional support to the roof structure. Consult a professional builder or engineer for recommendations.


How to attach 6×6 post to existing deck

Step:1-Determine the post location

Decide where you want to install the 6×6 post on your existing deck. Use a measuring tape and chalk line to mark the location.

Step:2-Prepare the deck surface

Clean the area where you plan to attach the post. Remove any debris or dirt using a broom or pressure washer.

Step:3-Drill the post hole

Use a post-hole digger to create a hole that is at least 3 feet deep and 12 inches in diameter. The hole should be wider than the post to allow for the concrete to be poured around it.

Step:4-Insert the post

Place the 6×6 post in the hole and ensure it is plumb and level using a spirit level. Use braces to hold it in place if necessary.

Step:5-Pour concrete

Mix concrete in a wheelbarrow or mixing tray according to the manufacturer’s instructions. Pour it into the hole around the post, leaving at least 2 inches of space at the top.

Step:6-Secure the post base

Once the concrete has cured, attach the post base to the post using bolts and nuts. The post base should be attached to the center of the post and flush with the deck surface. We recommend using concrete screws like the Caliburn XL Screw from GRK.

Step:7-Install the post bracket

Attach a post bracket to the post base using structural screws like GRK RSS screws. The bracket should be aligned with the post and flush with the deck surface.

Step:8-Attach the beam

Install the beam onto the post bracket, securing it with screws or bolts. The beam should be level and flush with the deck surface.  Use a plumbline to ensure it aligns perfectly with your post base.

Step:9-Add additional support

Install diagonal braces from the post to the beam if necessary for added support. Start by measuring the distance between the deck above and the post base below. 

Cut the 6×6 post to the desired length, subtracting about 1/16 inch to make up for imperfections in cutting. Drive it in place with a hand sled, fix required nails, check vertical alignment, and remove temporary supports for a secured post. 

Step:10-Finish the installation

Once all the connections are secure, finish the installation by painting or staining the post to match the existing deck.


An alternative process to attaching a 6×6 post to an existing deck is to use a post anchor.

Here are the steps.

Step:1-Determine the post location

Like the previous step, fix where you want to install the 6×6 post on your existing deck using a measuring tape and chalk.

Step:2-Prepare the deck surface

Now, clean the area where you plan to attach the post. Remove any debris or dirt using a broom or pressure washer precisely.

Step:3-Install the post anchor

Place the post anchor on the deck surface where you want to install the post. Using screws or bolts, you can effortlessly secure it to the deck.

Step:4-Insert the post

It’s time to place the 6×6 post into the post anchor and ensure it is plumb and level using a spirit level. Use braces to hold it in place if necessary.

Step:5-Secure the post

Once it is level and plumb, secure it to the post anchor using screws or bolts. Install diagonal braces from the post to the deck joists for additional support if necessary.

Step:6-Finish the installation

Check if all the connections are secured so you can finish the installation by painting or staining the post.

Using a post anchor can be quicker and easier than installing a post in concrete, but it may not be as sturdy as a post installed in concrete. 


Another alternative way to attach a 6×6 post to an existing deck is a ledger board.

It requires some straightforward steps to follow.

Step:1-Determine the post location

Locate the place for installing the 6×6 post on your existing deck with a measuring tape and chalk line.

Step:2-Preparing deck surface

Perfectly clean the area so that any debris or dirt can’t exist. Using a broom or pressure washer is encouraged for better results.

Step:3-Install the ledger board

At this stage, attach a ledger board to the existing deck using lag screws. The ledger board should be the same width as the post and placed where the post will be installed.

Step:4-Insert the post

Place the 6×6 post next to the ledger board just like the previous method.

Step:5-Secure the post

Once the base is level and plumb, secure it to the ledger board using lag screws. Install diagonal braces from the post to the deck joists for additional support.

Step:6-Finish the installation

Once all the connections are secure, it’s time to finish the installation process like the previous method.



How to attach 4×4 post to existing deck for roof

Attaching a 4×4 post to an existing deck is a simple DIY project that can be completed with basic tools and materials. Follow these steps to securely attach a 4×4 post to an existing deck.

Step:1-Determine the Location and Height of the Post

Measure and mark the location where you want to install the post. Use a level to ensure that the post will be plumb (vertical) once installed. 

Determine the height of the post based on your desired height and the height of the existing deck railing.

Step:2-Cut the Post to Length

Measure and cut the 4×4 post to the desired length, using a circular saw or handsaw.

Step:3-Prepare the Post Base

Use a drill and a spade bit to create a pilot hole in the center of the post base. Attach a galvanized post base to the bottom of the post using the recommended screws.

Step:4-Mark the Hole Locations

Place the post in the desired location and use a pencil or marker to mark the hole locations on the deck surface.

Step:5-Pre-drill the Holes

Use a drill and a bit that is slightly smaller than the diameter of the screws to pre-drill the holes in the deck surface.

Step:6-Attach the Post to the Deck

Position the post base over the pre-drilled holes and insert the screws or bolts through the post base and into the deck. Then, securely tighten the screws or bolts using a wrench or socket set.

Step:7-Install the Post Cap and Railing

Attach a post cap to the top of the post using construction adhesive or screws. Install the deck railing on the post according to the manufacturer’s instructions.

By following these steps, you can successfully attach a 4×4 post to an existing deck and create secure and stable support for your deck railing.


Here are two alternative ways to attach a 4×4 post to an existing deck.

Using a Post Anchor Bracket

  • Measure and mark the location of the post on the deck.
  • Place a post anchor bracket on the mark and drill pilot holes through the bracket and into the deck.
  • Insert lag screws through the bracket and into the deck using a socket wrench.
  • Place the 4×4 post into the bracket and secure it with screws or bolts.
  • Lastly, attach the post cap and deck railing.

Using a Through-Bolt and Washer

  • Start similarly to the previous step by measuring and marking the location.
  • Drill a hole through the center of the post and deck using a drill and spade bit.
  • Insert a through-bolt and washer through the hole and secure it with a nut using a wrench.
  • Finally, attach the post cap and deck railing.

However, the size of the bolts or screws may vary depending on the thickness of the deck and the weight of the structure it needs to support. It’s important to use the appropriate size and type of fastener the manufacturer recommends for optimal stability and safety.


Should I take permission from authorities to install a roof over the deck?

Yes, you may need to obtain permission from the authorities before installing a roof over your deck. Building codes and zoning regulations vary by location, so checking with your local building department or planning office is essential. 

A permit is often required for any structural additions to your property, including roofing. Failing to obtain the proper permits could result in fines or even the removal of the structure.

In the United States, each state has its own building codes, which local governments enforce. The International Building Code (IBC) is used as a model code in many jurisdictions and sets forth minimum requirements for building safety and health. 

For more information on building codes and permit requirements in your area, visit the website of your local government’s building department or planning office. For example, in New York City, you can check the Department of Buildings website for permits and code compliance information.

Here are a few consequences of not following the laws:

  • Legal Penalties: Not following the laws can result in legal penalties such as fines, imprisonment, or probation.
  • Civil Penalties: Failure to follow the laws can also result in civil penalties such as lawsuits, damages, or injunctions.
  • Reputation Damage: If you don’t follow the laws, it can damage your reputation and lead to a loss of public trust.
  • Unsafe Environment: Ignoring safety regulations or building codes can result in unsafe working or living conditions, putting yourself and others at risk.


Conclusion

Before understanding how to attach deck roof support posts, careful planning and adherence to building codes and regulations should be estimated. Anchor brackets and buried posts in concrete footings are popular methods for attaching support posts. 

When using 4×4 posts, consider using larger diameter anchors or footings to ensure stability. 6×6 posts can provide additional stability and may require less spacing. 

It’s also important to use high-quality materials and proper installation techniques to ensure the longevity and safety of the structure. 

By following these guidelines, you can create a strong and durable deck roof that will provide protection from the elements and years of enjoyment.

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