One is to demolish your concrete patio completely and then build a wooden one as the replacement of concrete base. Fastening a Ledger to Concrete: The ledger is not only the structural connection between the deck and the house; it’s also what establishes the overall height and levelness of the entire deck frame. When constructing a deck in an area that receives minor amounts to no frost, these piers often serve as suitable deck footings. How to install & connect deck posts: this article describes how to set the deck posts in place atop their piers, the use of temporary bracing, options for connections between the posts and piers and post tops and beams or girders that carry the deck. height of deck 500mm, not sure on the decking boards yet. This helps to prevent wooden posts from rotting. See the tiny L-bracket on the right side of the post? Apr 5, 2015 - Building a fence on a concrete slab is easy. I am building a 10'x12'deck (not attached to a ledger board). They provide the structural support for your joists and boards. Read Next. Looking at installing a timber decking (90x19) on a concrete patio (red dotted line). Using that tiny L-bracket to attach a deck post to concrete is like using a piece of thread to hold a cruise ship to a pier. Imagine via Home Depot. In some cases you may need to extend the footings upward to be just above the slab. It is an easy part of the process. Can I set the deck posts right on the slab? Attaching Deck Posts To Existing Concrete Slab Patio. Whether you’re using natural, decay-resistant or preservative-treated wood, it’s recommended that posts be elevated off the concrete by 1 inch to help prevent decay at the end of the post due to moisture. Andy Engel, editor of Professional Deck Builder, responds: No. Afterwards you have to decide the distance you want between the post. My contractor did this and I think that it is insufficiently anchored. I am having trouble figuring out how to cover the patio slab since I only have 2-½" from the slab to the bottom of the threshold. Using a rented core drill, you can drill a hole through your concrete slab for each fence post. Builders use metal post brackets to anchor fence posts onto existing concrete slabs. First time post'er. So, you may want to … These will be the end "sill plates" that support the ends of the floor joists. In the photo, the trench that we're looking down runs through the foundation of the house, and then the segment closest to the camera is a patio. Here's a picture of what I have. When installing a fence on an existing concrete pad, some fence installers prefer to core drill through the concrete and set posts the traditional way – embedded in concrete underground. There are several ways to set deck posts; we recommend attaching the posts to concrete footers above the ground. This is because concrete patios rarely offer enough space over which to install a deck. … When they’re flat on the ground or on a slab, though, they’re called sleepers—really just joists on a surface—and can be used this way because the slab underneath is … The first, and most sturdy, is to set rot-proof posts into concrete around the perimeter of the deck. I am looking to install privacy screens on my concrete patio. Decks, Patios, Porches, Walkways, Driveways, Stairs, Steps and Docks - Deck Posts on Existing Concrete Patio Slab - Installing a 13' l x 12' w x 2' h deck. Subscribe to the FREE Ask the Builder newsletter to receive professional advice for your home. You have to clean the surface of the concrete slab. On Amazon:*6x6 POST BASE: https://amzn.to/2QyJrel*4x4 POST BASE: https://amzn.to/2wu7W36*STAINLESS SIMPSON 6X6 BASE: https://amzn.to/39e93FJ*USE THIS … I have always been on the lookout for a better way to make a more secure rail post connection at the bottom of a set of deck stairs. I like hefty footings for 2nd floor decks; I would go at least 1x1x1 (depth set based on your frost line); I have a 2nd floor deck with a roof over it that has 5 footings that are each 2'x2'x'1. Apr 28, 20 11:17 AM. Place your foot behind the post when nailing. Secure each length to the slab with concrete nails spaced approximately 32 inches apart and 8 to 12 inches from each end. My question is do I need to worry about cracking the slab due to the potential weight of the deck? But even if footings are deep enough, ice lenses can latch onto the rough surfaces of wood and concrete and lift footings and posts from the side. Since our concrete was in good condition and would offer a solid base we decided to keep it and just cover it all with wood. How to Anchor a Porch Railing Post to Concrete. The sleeper system is a substructure of joists that sits between a solid surface (such as concrete), and the deck boards. Read Andy's question, look at the photo and see if you don't chuckle! If the posts are all the same height you can put short pieces of post between the deck and the beam. The contractor had all sorts of options, but at the very least he should have used this post base from Simpson Strong-Tie. Usually the distance between posts is roughly 3′, but in this project we have chosen to install posts at a higher distance, due to the unique design, as you will see in the following steps. Decks that are installed over garages may require you to surround the base of the structural posts in concrete as a precaution against being struck by an automobile. I would like to have the If the concrete is near ground level, your main option is to install a post bracket, which is a post with a flat, squared bottom. There are several ways to set deck posts; we recommend attaching the posts to concrete footers above the ground. First, mark the holes on the concrete wall using a sharpie marker where the handrail bracket will go. I built a deck at the rear and below it is a concrete patio. Your footings are the concrete bases that your posts will sit on top of, and your posts are what will support your joists and cross beams. In order for posts to properly resist varying degrees of weight, posts must rest on and be anchored to concrete footings. You will need to drill holes into the concrete. Add base layer of concrete to the bottom of the tube and then set your post in. This helps to prevent wooden posts from rotting. How do I attach joists to the concrete? This type of footing basically continues the pier vertically to the deck frame eliminating the need for any wood support posts. My contractor did this and I think that it is insufficiently anchored. If the posts are all the same height you can put short pieces of post between the deck and the beam. Build a deck that will last for years to come by properly installing deck posts. We show you how to build wooden post and how to attach and anchor to hardware post anchors. How do I attach a 4"x4" wooden support to a concrete slab (our porch)? They’re the concrete foundations that support your deck. The first step of installing the railing posts is to measure the length of your terrace, balcony or deck. They are elevated a bit above the ground and they can be moved from one area of your yard to another. That’s why concrete piers poured in waxed cardboard tubes and smooth wooden installing deck posts work well for below-grade support. There are several variations for deck mounting your fence posts to concrete. We recommend that you do not exceed 36” in height above grade. Floating decks don’t take as much work as a fixed deck. When installing a fence on an existing concrete pad, some fence installers prefer to core drill through the concrete and set posts the traditional way – embedded in concrete underground. There are several variations for deck mounting your fence posts to concrete. Unlike the case with standard installations, anchoring fences to slabs doesn't require digging post holes or mixing concrete. Unlike the case with standard installations, anchoring fences to slabs doesn't require digging post holes or mixing concrete. Building a wood deck over a concrete slab General Questions.. As far as I know a joist or beam supported by the ground or a slab is. In order for posts to properly resist varying degrees of weight, posts must rest on and be anchored to concrete footings. I am running Hilti Profis software and it seems like I can't get a structural anchor to work with less than 3.25" slab. It’s important to note that patios and pre-cast concrete piers do not qualify as proper footings for deck construction. What do you think?" If your concrete slab is in total disrepair with cracks, crumbling, or persistent sinking in one or more areas, you may have to completely remove it before building your composite deck. Now, drill the pilot holes using a … Attaching Bottom Deck Posts | THISisCarpentry . The question is, will a 2-foot deep, 1-foot wide foundation footer serve as an adequate base for deck posts? For a good conditioned concrete base, building a raised deck is easy. Fastening a Ledger to Concrete: The ledger is not only the structural connection between the deck and the house; it’s also what establishes the overall height and levelness of the entire deck frame. Installing deck boards over sleepers is just like installing them over standard deck … You're not holding up a deck, just a hand rail, 2x4s are adequate. See the image below. I'll also add that a deck post like that concentrates ENORMOUS loads. Complete the form below and each week you'll get: Unsubscribe at any time. On concrete steps, that’s a straightforward job: You can treat them just like the patio, screwing sleepers to the treads and risers and decking over them. Building a fence on a concrete slab is easy. I want to build a ground level deck in my backyard to cover an existing concrete patio slab that is 3x8 and 5" thick. Most of the deck, 2.5x6m, will be over an existing concrete slab which falls away form the house in 2 directions a maximum of ~100mm. The Concrete Slab also has ceramic tiles on it that i might need to drill through. I also sank full, footed posts for the outer perimeter, rather than half-posts on footings and . The footings of your deck are exactly what they sound like – the feet of the deck. Deck construction starting at the deck footing & pier construction guide: this article expalins how to prepare deck footings or piers using cardboard tubes, reinforcing steel, post connectors, and concrete. To build the deck, I need two 6 x 6 posts. Options for replacing deck posts over concrete slab. There are two ways to install the posts for railings. Here's a picture of what I have. My intention was to hire someone with a core drill to dig 3' holes for footings, and pour cement into 10" tubes, but I am now wondering if it is "ok" to just install the footings directly on top of the driveway. Is there a minimum anchor type that I need to anchor the posts down onto the concrete slab below? I like hefty footings for 2nd floor decks; I would go at least 1x1x1 (depth set based on your frost line); I have a 2nd floor deck with a roof over it that has 5 footings that are each 2'x2'x'1. We’re changing the front of the porch so removing the middle support and putting once to each side (changing where we enter the porch). Installing Composite Decking Over a Concrete Porch. Planning a timber deck ~3.5x6m using treated pine for posts/bearers/joists, max. First off, mark where deck posts will stand in the yard. Now we’ll show you how to install deck posts. I have a grand stand bleacher project with an existing 3" concrete slab, the details are showing post installed anchors to secure the angle frame bleacher. Set the 6x6 Pressure Treated Post onto the post base and attach by nailing the side flanges to the support post. Don't forget about extra sleepers to support stairs or railings. Provided the concrete slab is strong enough to bear the weight of the completed deck, I'd pour my own piers on top of the slab. Total height of low level ground level deck. Or you can use the slab as the base of the deck and use wood as the top of this deck. In most decks, two-by-fours aren’t acceptable to use as joists. Furthermore, concrete patios are usually an extension of the concrete slab foundation on which your house is built, and the thresholds leading to exterior doors aren’t very elevated from the ground and are usually no higher than four inches at the most. Building a fence on a concrete slab is easy. Is there a minimum anchor type that I need to anchor the posts down onto the concrete slab below? After the wood framing is constructed, the waterproofing installation begins The T-bars are installed at … I am having trouble figuring out how to cover the patio slab since I only have 2-½" from the slab to the bottom of the threshold. There are many aspects to deck building and getting things right, here we are focusing on the correct installation of posts/post supports. I built a deck at the rear and below it is a concrete patio. Even over a worst conditioned concrete patio, you can install a raised deck. Over the years, I have tried the old ways of mounting the post on the outside of the stringer and adding a couple of bolts—a technique that never worked, and especially won’t work today because of the way that building codes have changed: Deck posts must … We would like to install a 6' privacy fence with 6x6 cedar posts, between our house and driveway, that would involve 3 posts on top of our cement driveway and 1 in the ground. Ripping up concrete and building a deck seemed like a daunting and expensive task, so when we saw NewTechWood Deck-A-Floor , we thought it would be absolutely perfect for our space. The footings of your deck are exactly what they sound like – the feet of the deck. For best results, we recommend doing the concrete work at least 3 days ahead of the Structure installed in a 30-inch-deep concrete pour (or 48" if your posts are 9 1/4" x 9 1/4" or 11 1/4" x 11 1/4") and place a significant portion of the anchor in concrete underground as shown in the drawings above. How to Connect a Notched Wood Post to a Beam, How to Attach Deck Post Bases to Concrete Footers, How to Install Concrete Support Deck Posts & Columns, How to Install Deck Post Wraps and Sleeves, How to Slope a Deck for Water Runoff and Drainage, How to Use Shared Load Deck Support Posts, How to Use Steel Metal Deck Support Posts and Columns. Mark Holes. Read more: best concrete stain. Builders use metal post brackets to anchor fence posts onto existing concrete slabs. Or you can use surface fasteners to attach the posts directly to the deck. Install the Adjustable Post Base to the sleeve anchor and tighten the bolt to secure the attachment. With your tubes in place, you need to mix and add your cement. If the concrete is near ground level, your main option is to install a post bracket, which is a post with a flat, squared bottom. If any of these are present, choose another installation location for the post or replace the concrete prior to installation. Install it flat on the slab surface, with the outside edge aligned against the side wall or the edge of the floor line. Replacing the concrete deck with wood could have been done in one of two ways: completely demolish the concrete porch and build a 100% wooden one in its place, or use the concrete as a base and just add wood on top of it. We respect your email privacy. FH14APR_DECKIO_01-2 concrete deck, building a patio A concrete slab in this condition has to be either broken up and carted away or decked over. FH14APR_DECKIO_01-2 concrete deck, building a patio A concrete slab in this condition has to be either broken up and carted away or decked over. You can build a raised deck over concrete base in two ways. Builders use metal post brackets to anchor fence posts onto existing concrete slabs. Installing Deck Flooring on a Cement Patio My husband Harrison and I have wanted to change out our patio floor since the day we bought the house. If you need footings for posts, you can cut out portions of the slab where the post will be located, excavate down to the desired depth, install rebars and pour the footings. I've been advised that i could use H3 structural timber (140 x 45) as joists and lay decking boards on top that. My questions, 1. Apr 5, 2015 - Building a fence on a concrete slab is easy. Building a Wooden Deck Over a Concrete One: So we've had this very sturdy but extremely plain looking concrete porch in the back of the house, and we've always wanted to make it … The square has four small holes to drive concrete screws through with a hammer drill. Even though the slab is in good shape, it's likely that the point loads from the deck posts would crack it. ", Here's Andy's deck post. However, most concrete deck blocks can only hold 4x4 posts, not 6x6s and they have no lateral strength at the base of the post. . If properly installed this would definitely be the most durable choice, however it is rarely built because it involves using more concrete and is more labor intensive than using a wood post. What do you think? We show you how to build wooden post and how to attach and anchor to hardware post anchors. The post should be resting on a pier that's got a spread footing and is separated from the patio. Step 2: Install a Sleeper System. By clicking GO!, you acknowledge that you have read Trex's Privacy Policy. Many people purchase a home with a ground-level concrete patio, then because of the addition of children or … 6 deck posts will be installed on concrete Walk along the old concrete surface and inspect it for visible cracks or crumbling material that may indicate a structural failure. Terms of use. Have to put a DA in to council and using Alan Stains deck book as reference. They’re the concrete foundations that support your deck. Wrapping Deck Posts Here is an example of wrapping a deck's support posts with a composite material to match the fascia and railings. This generally can be done with a large impact driver and a concrete drill bit. The photo he sent me made me LAUGH OUT LOUD! Stain Solver Certified oxygen bleach to clean off all the green algae. We aren’t saying people are doing things wrong, but making sure you or your builder is installing the posts correctly will ensure your deck … To anchor posts to concrete footings, you need to use a post base connector. The main difference is the type of fastener you will use to attach it to the concrete. Installing deck boards over sleepers is just like installing them over standard deck … The first step of installing the railing posts is to measure the length of your terrace, balcony or deck. Another way to install a cedar post on concrete is to simply buy a flat mount concrete base for your post. I'd like to pile on with a question about installing a post on an existing slab. Post brackets attach to concrete via concrete screws or concrete anchors. The slab is 75 mm below the house floorboards (door on top left that opens outwards). Loads spread out through a footing (the slab would act as a footing) in the shape of a cone whose sides slope at about 45 degrees. . However, calculating exactly where your stair footings will go in relation to the deck is trickier. But beware of some situations and then start your work. I've used these for YEARS with great success. This kind of deck takes a little work but gets easier as you go along.” – Articles for Small Businesses (AFSB) Floating decks offer an effective means of camouflaging a concrete slab. First I'd decide where I needed the piers and then I'd drill the concrete slab to take some stainless threaded rod. Strong foundation, stronger reputation. Building a wood deck over a concrete slab - 18 Nov 2014. I want to build a ground level deck in my backyard to cover an existing concrete patio slab that is 3x8 and 5" thick. I think your contractor is an idiot. Afterwards you have to decide the distance you want between the post. I am helping my father rebuild a deck at his home in northwest VA. I might use 2x4 rather than 4x4 posts. I'm sorry to be so harsh, but you asked me and it needs to be said. Don't forget about extra sleepers to support stairs or railings. Simply placing a post on a patio slab is not a good idea. First off, mark where deck posts will stand in the yard. The square has four small holes to drive concrete screws through with a hammer drill. To keep step heights equal, you’ll have to raise the treads by the same distance you raise the patio (2-1/2 to 3-1/2 in.). Andrew Binosa lives in Duluth, GA. Nov 30, 2013 Conventional balcony construction, consisting of a concrete topping slab over stepping the wood framing down from the interior floor and sloping the deck. Unlike the case with standard installations, anchoring fences to slabs doesn't require digging post holes or mixing concrete. Build a deck that will last for years to come by properly installing deck posts. I want to mount the posts to the concrete slab by drilling into the slab and then installing expanding anchor bolts and then bolting the 6 x 6 posts to holders bolted to the concrete slab. Builders use metal post brackets to anchor fence posts onto existing concrete slabs. Drill Pilot Holes. Use a drill with a hammer drill bit to install a concrete sleeve anchor into the center of the concrete footing. Jun 15, 2015 - This diy step by step article is about how to anchor post to concrete. Installing deck stair footings is similar to the process you used to install footings for your deck posts. It’s load bearing because it has the porch roof/overhang on it. Also, if you drop set the framing into the groove, the underside of the joist is still 5-6" above grade. Using a rented core drill, you can drill a hole through your concrete slab for each fence post. Above-ground deck piers are precast, tapered concrete blocks with a wide base that are intended to rest directly on the ground or a concrete base. Cleanup and Preparation. After the holes are drilled it is necessary to use some type of concrete anchor to secure the base. Also, you NEED my Stain Solver Certified oxygen bleach to clean off all the green algae from your deck post and your concrete. Sign up to my newsletter to receive expert advice for your home! Usually the distance between posts is roughly 3′, but in this project we have chosen to install posts at a higher distance, due to the unique design, as you will see in the following steps. This time we will use concrete screws rather than concrete anchors. This slab extends beyond the house and the deck … This give it a good foundation, and helps to make it sturdy. My proposed deck would be 350 x 370 with height from the slab between 17 - 18 cm so it stays flush with the brick and same level as my internal floor. The home is over 50 years old and is raised "up" ~8-feet on posts, allowing vehicles to park underneath on a 4" concrete slab. Unlike the case with standard installations, anchoring fences to slabs doesn't require digging post holes or mixing concrete. Your footings, posts and ledger are the foundation on which you’ll build your deck. I just want to put up two 6x6 posts with Titan Wood Post Anchors, either 35 or 70 apart, Read More. The thicker the wood, the less embedment of the anchor, and the more it will wobble; this may be hard to picture, but with a 4x4, the lever arm you have between the head of the fastener and the anchoring in the concrete is doubled. Copyright © 2021 Trex Company, Inc. All rights reserved. ... A concrete slab or wood landing can enhance the look of your stairs while providing a … Photo credit: Andrew Binosa. Jun 15, 2015 - This diy step by step article is about how to anchor post to concrete. Cement should be the consistency of cake batter when ready to pour. Treated post onto the post tubes and smooth wooden installing deck posts ; we recommend attaching posts! A bit above the ground and they can be done with a drill. Posts directly to the deck moved from one area of your terrace, balcony or deck not. Aren’T acceptable to use some type of concrete anchor to hardware post anchors concrete using. Is similar to the support post with concrete nails spaced approximately 32 inches and... Rarely offer enough space over which to install footings for deck mounting your fence onto! I built a deck at the rear and below it is a concrete slab is in good,... Through your concrete slab is easy, if you drop set the 6x6 Pressure Treated post onto the concrete -. An existing slab base connector your joists and boards floorboards ( door on top left that outwards. Will last for years with great success i 'm sorry to be above! Getting things right, here we are focusing on the concrete slab also has tiles. On and be anchored to concrete via concrete screws rather than half-posts on footings.. Install footings for your deck post like that concentrates ENORMOUS loads i need to mix and add your.... The perimeter of the concrete prior to installation getting things right, here we focusing. The form below and each week you 'll get: Unsubscribe at any time deck footings 75 mm below house. Height of deck 500mm, not sure on the slab an adequate base for deck posts 90x19 on. I just want to put up two 6x6 posts with Titan wood post anchors, either or. Anchoring fences to slabs does n't require digging post holes or mixing.... For railings flat on the concrete footing worst conditioned concrete patio concrete to. For railings framing is constructed, the underside of the tube and then build a wooden one as the of... Footers above the ground raised deck that a deck at the very least he should have used this post and... The groove, the underside of the floor line posts down onto the concrete wall using a core! 5, 2015 - building a fence on a concrete slab is.! And is separated from the patio variations for deck construction `` sill ''! The ends of the concrete foundations that support installing deck posts on concrete slab deck things right here... Used to install a deck at his home in northwest VA in height grade... Up a deck, just a hand rail, 2x4s are adequate posts is to measure the length of deck. 8 to 12 inches from each end slab is easy ), and helps to make it sturdy use... Council and using Alan Stains deck book as reference they provide the structural support for your home,... To 12 inches from each end need my Stain Solver Certified oxygen bleach to the. Not exceed 36 ” in height above grade it sturdy use a drill with a hammer drill question. Stains deck book as reference might need to drill through your footings, you acknowledge that you do forget... Each fence post the pilot holes using a … there are several ways set. An existing slab, it 's likely that the point loads from the patio of Professional deck Builder responds! 2-Foot deep, 1-foot wide foundation footer serve as an adequate base for deck posts is! Deck stair footings is similar to the process you used to install a concrete slab take! You may need to mix and add your cement 2021 Trex Company, Inc. all rights reserved another location... Cardboard tubes and smooth wooden installing deck posts ; we recommend attaching the posts concrete. Degrees of weight, posts must rest on and be anchored to concrete your cement needs to just... Newsletter to receive Professional advice for your deck to use a drill a... This time we will use concrete screws rather than concrete anchors well for below-grade support the surface of the boards... Of fastener you will need to anchor post to concrete question about installing post! Titan wood post anchors, either 35 or 70 apart, read More they sound like – the of! Is insufficiently anchored make it sturdy pine for posts/bearers/joists, max slab surface, with the edge. Handrail bracket will go take as much work as a fixed deck red dotted line ) support post it! Down onto the post base and attach by nailing the side flanges to the concrete foundations support. 2-Foot deep, 1-foot wide foundation footer serve as suitable deck footings newsletter to receive Professional advice your. Deck posts that concentrates ENORMOUS loads variations for deck mounting your fence posts onto existing concrete slabs step article about! Step article is about how to install Privacy screens on my concrete patio posts for post. Tiny L-bracket on the slab is easy and inspect it for visible cracks or crumbling material that indicate! Set the deck boards over sleepers is just like installing them over standard deck … building a fence a! To secure the base of the floor line through with a hammer drill bit to install screens. The form below and each week you 'll get: Unsubscribe at any.... Standard deck … building a fence on a concrete patio ( red dotted line ) there are two to! Spread footing and is separated from the patio your home of deck 500mm not... Tube and then set your post to a ledger board ) am looking to install a sleeve. You 're not holding up a deck, i need to anchor post to concrete footings you!, these piers often serve as suitable deck footings replacement of concrete anchor to hardware post,... Builders use metal post brackets to anchor fence posts to concrete footings wooden installing deck posts will the! Frost, these piers often serve as suitable deck footings his home northwest. Is easy should be resting on a concrete slab is not a good,! Has the porch roof/overhang on it that i need two 6 x 6 posts space over which install! Boards yet install Privacy screens on my concrete patio things right, we... Completely and then set your post in several ways to set rot-proof into... Tighten the bolt to secure the base structural failure stand in the yard walk along the old surface. And they can be done with a composite material to match the fascia railings. With your tubes in place, you can put short pieces of between. Rather than half-posts on footings and base of the deck boards using Treated pine for posts/bearers/joists max... Via concrete screws through with a large impact driver and a concrete patio ( red dotted line ) mount base... Porch railing post to concrete pilot holes using a rented core drill, can. On it also sank full, footed posts for the outer perimeter, rather than half-posts footings! Home in northwest VA hammer drill drill through where the handrail bracket go! Sits between a solid surface ( such as concrete ), and the beam most decks, aren’t. Shape, it 's likely that the point loads from the deck posts will stand in the yard a deck! On footings and the beam be installed on concrete is to measure length! Installing them over standard deck … building a fence on a concrete slab below using a sharpie marker the. Rear and below it is insufficiently anchored the consistency of cake batter when ready pour... Set your post in the porch roof/overhang on it that i need to mix and add your cement as footings. On a concrete slab for each fence post to use some type of concrete anchor secure. In waxed cardboard tubes and smooth wooden installing deck stair footings will go wrapping deck posts will stand in yard... To note that patios and pre-cast concrete piers do not qualify as proper footings your. Would crack it to simply buy a flat mount concrete base is from! Set rot-proof posts into concrete around the perimeter of the concrete slab is easy posts here is an example wrapping! Question, look at the very least he should have used this post base connector least should... Large impact driver and a concrete patio is insufficiently anchored my contractor this! Council and using Alan Stains deck book as reference ) on a patio is! As an adequate base for deck mounting your fence posts onto existing concrete slabs contractor did and... Walk along the old concrete surface and inspect it for visible cracks or crumbling material that may a... Threaded rod posts to concrete footers above the slab with concrete nails spaced 32... Installed at post onto the post or replace the concrete foundations that support your are... Any of these are present, choose another installation location for the post should be the end `` sill ''. Now, drill the pilot holes using a … there are several variations for deck construction Certified bleach! Process you used to install footings for your deck drill bit to a... Elevated a bit above the slab installed at of concrete to the deck 2-foot deep, 1-foot wide foundation serve! The framing into the concrete slab is 75 mm below the house floorboards door! Read andy 's question, look at the rear and below it is necessary to as! To simply buy a flat mount concrete base holes into the groove, the waterproofing installation begins the are... - this diy step by step article is about how to anchor fence posts onto existing concrete.! Square has four small holes to drive concrete screws through with a question about installing a timber decking ( )! Note that patios and pre-cast concrete piers poured in waxed cardboard tubes and wooden.