Deck Railing Repair Using Granite and Composite

Our deck wraps around three sides of our house. The longest run is 46'. Two sections are a story off the ground. The third is about 4' above the ground. This means, good, solid railing makes the difference between being safe or in danger using the deck.

The deck was built nearly 4 decades back. My wife says the builder was worried about the length of the runs, because of the issue of railing stability. The builder's worry was justified, because a long railing run needs bracing, to keep it from moving, and growing worse over time.

Our railing sections near where runs joined at 90-degree turns were fine, because the turns worked as bracing. However, twenty-three feet out, at the middle of our longest run, the railing would move as much as four inches, with little effort. A, potentially, very dangerous problem. If someone were to trip and land against it, it could give away.

Then there is the matter of that the deck was all built from wood and the decades had not been kind to it. The railing cap was a 2x6 mounted horizontally, with no tilt for drainage, and it was attached via deck screws through the top. Because of the type of materials used for the cap, and the methods used to secure it to the 2x support under it, there were a couple spots requiring replacement. Other spots were on their way to needing replacement too.

MATERIALS:

(1) Composite decking of your choice.

(2) Z-clips for mounting table tops to supporting aprons. Always buy more than you need, and buy enough to install clips about every 10" to 12" on both sides of the cap.

(3) #8 5/8" screws (any longer and the screws might go through the decking, piercing the top. Again, buy more than you need. Plan on dropping a few here and there.

As noted, I tried using #6 square drive screws, but they kept slipping off the driver bit, and were hard to hold, resulting in a lot of lost screws and finger pinches. So stay with the #8's.

(4) Elastomeric caulk matching, as closely as reasonably possible, the composite you're using.

(5) Your choice of material to cover the sides of any brace cap supports you install (e.g., sheet metal, or cedar).

(6) Deck screws: To secure the supports for the brace cap to the deck railing.

(7) Primer and paint: For any raw wood (e.g., railing brace cap braces).

(8) Scrap/Salvaged granite: This is free if you look and, when asking, tell the folks you'll clean up any mess you make (e.g., re-stack the scrap you picked from back on pallets). Granite fabrication shops have to pay to dump it, so many will let you take scraps for free.

So that I could come back, I ALWAYS left the scrap piles in better shape than I found them. That is, I left nothing on the ground. It all went back atop the pallets and was stacked so they could lift it without it falling off.

Cut, rounded over and polished, the granite makes for the perfect cover for outriggers and composite butt joints. It will outlast the composite 1000 (or a million) to one.

See the photos for some of the granite I was allowed to cart off for this project, to make planter stand covers and so on.

(9) Painter's tape: This will be needed when you caulk between the composite and the end or outrigger caps.

(10) 2 x 4's to build the supports the caps that cover the rail brace supports will rest on.

(11) Construction adhesive to attach the granite caps to the supports.

(1.0) A biscuit machine, which is used to make slots in surface edges that will be joined using special biscuits, but will just be used to make slots, into which the table-top mounting clips will be installed.

(2.0) A miter box with about a 60 tooth, 10" carbide blade, or the equivalent. An 80 tooth, 10" blade would be fine too. I wouldn't go more coarse than the 60 tooth blade, because you want relatively smooth cuts.

This is to make cuts on your composite, Also, if you do add braces, this will simplify cutting the brace cap supports of 2x4 stock.

It will be helpful if you install a zero clearance fence and base to your miter for these cuts. And, let the blade come to a full stop, before lifting it after a cut, and you won't launch the pieces you just made.

This can be done with a circular saw, or even a decent jig saw, but you'll have to work a lot harder for the end result.

(3.0a) A saber saw, to make cut-outs, to allow you to install the cap brace with the railing brace in place. An advantage of this method is, adjusting and moving the conduit used for the brace is easier than the alternate of just drilling a hole.

or

(3.0b) You could opt for just drilling a hole in the 45-degree brace of the granite support, for the outriggers/railing braces to go through, to attach them to the deck and vertical posts, but it may make installing the railing brace, and adjustments, more complicated.

(4.0) Impact driver and bits.

(5.0) A drill and bit to make the holes needed to mount the braces to the deck and railing.

(6.0) Measuring tape.

(7.0) Caulk gun.

Note, you don't have to measure where you put all your kerfs (the distance between them). Mark a couple and just try to stay with that pattern.

(8.0) If adding bracing, and you cover the braces with granite or composite caps, a level to insure the cap support is horizontal.

(9.0) Ball peen hammer, to flatten the ends of the conduit.

(10.0) A small anvil would be nice, but you may be able to find a rock or other solid, dense surface to lay the ends on.

(10.1) I didn't try it, but it may be clamping the ends in a vice would flatten the ends. If I went that route, I'd do just a bit at a time, to see how it went.

(11.0) For cutting and polishing the granite, you'll need:

(11.1) A circular saw or a tile saw to cut the granite. If you don't want to invest in a tile saw, you could buy an inexpensive circular saw to dedicate to that purpose.

POWER YOUR TILE SAW or CIRCULAR SAW FROM A GFI OUTLET, FOR SAFETY, BECAUSE YOU'LL BE USING ELECTRICAL EQUIPMENT AROUND WATER.

(11.2) A straight edge to act as a guide, if using a circular saw.

(11.3) Clamps (e.g., C-clamps, F-clamps) to secure the straight edge to the granite.

(11.4) An angle grinder for the grind stone and polishing pads.

AGAIN, FOR SAFETY, POWER YOUR GRINDER FROM A GFI FOR SAFETY, BECAUSE YOU'LL BE USING ELECTRICAL EQUIPMENT AROUND WATER.

Also, consider a more expensive variable speed grinder. Though they do cost significantly more, it would be a lifetime investment for all but a few, and the variable speed will allow you to do things with the grinder a standard, 10,000 RPM, grinder would be far too fast to do.

(11.5) A threaded grind stone sold by granite working supply sites with 5/8" threads to fit your grinder.

(11.6) A threaded four inch (4") hook-and-loop pad for your angle grinder.

(11.7) A set of four inch (4") hook-and-loop diamond polishing pads for granite in the following grits:

100, 200, 400, 800, 1,000, 1,500, 2,000, 3,000.

(11.8) If you plan on playing with granite scraps a lot, you may want to look into granite router bits, like in the photo, to make more pronounced and consistent round-over edges.

(12.1) EYE PROTECTION

(12.2) EAR PROTECTION

(12.3) LUNG PROTECTION (an N-95 mask should suffice). Though you may not see it, the pads and blades toss a lot of water mist, and that mist is laden with dust from the diamond blade and pad cutting or polishing operations.

(13.1) Waterproof shoes (I have big, floppy rubber boots I can just step into.

(13.2) Rubber gloves will both keep your hands dry and give you added protection against shocks.

(13.3) I have a waterproof apron I wear. It reaches down to my feet and keeps me from getting soaked from all the water the tile saw and grinder-polisher throw off.

SIDE NOTES:

When contemplating the price of purchasing tools, keep in mind, a project like this would cost thousands upon thousands more, if you contracted it out.

Too, you can use the equipment on other projects years down the road. For example, you can replace worn tops of small tables with granite you've cut and polished. For example, I replaced the top of a bent-wood planter stand, and used a long piece over an aquarium stand.

(1.0) I focused on the problem of stabilizing the long railing run movement before I tackled the railing cap issue.

(2.0) I considered adding 4x4's that would extend about seven feet above the deck and tying them back to the roof by way of a slightly tilted 2x6 mounted on edge, but then thought about my days of riding the Washington ferry system. If you look at photos of the rails on the observation decks, you'll see they have pipes approximately 1-1/2" in diameter running back from the railing tops to the decking at about a 40-degree angle, and they are installed every few feet and make the already well-built railing even more stable.

(3.0) I had 3/4" conduit a friend gave me from when his workplace performed a major renovation and was hauling all the old stuff to the landfill. I cut the conduit into forty-two inch lengths, then hammered about 4" of both ends flat, to allow me to secure the flattened ends to a vertical rail post and to the edge of decking.

(4.0) Once the ends were flat, I bent them at the job site, to get the right angles. Some of the angles changed, because of the pattern of the decking was different on the different sides of the deck, but adjusting the angles was one of the easiest things about the project.

(5.0) Drilling the holes the bottom deck screws would go through, when running the screw into the side of the decking, at a slight angle, was best done at the time the braces were installed. This is because the braces moved in or out from the railing slightly, depending on the decking material pattern (mine had 2x4's and 2x6's, and east side is 10' deep, the sought 6' deep, and the west is 8' deep.

(6.0) I installed three braces on the long rail run. Had the run made a ninety on the west end, like it did on the east end, I could have stabilized the railing with two, but, because the west end terminated at a gate leading to a one-story stair, rather than a ninety-degree turn, I had to add a brace there too. The West side got two braces, and the east side got one.

(7.0) After the braces were installed, the improvement was immediate and obvious. The railing went from moving as much as four inches at the center of the long run to, at most, moving about 1/8" to 1/4" (see photos of the angled braces).

(1.0) After installing the six stabilizing braces, I was concerned someone might trip on them. To minimize that possibility, I decided to cap them with pieces of granite I scavenged from a pile a fabricator earmarked for disposal and gave me permission to sort through.

SIDE NOTE: I was VERY careful not to make a mess for the granite fabricators, and even tried to improve on what I started with. First there is that he was nice enough to allow me to take the granite, second, I might want to come back for more one day.

(1.1) Simply put, my intention was, to take advantage of the mechanical improvement (bracing) to make improvements in the aesthetics of the railing too. For that reason, I chose to use granite from the above-mentioned scraps.

(1.2) The granite caps I would be covering the braces with was thicker than the composite decking material, so worked perfectly to butt the composite railing cap against. The thicker granite worked well for hiding composite ends. Without them, I would have had to butt composite up against composite, which would not have looked as good and would have been more of a feat, to get a smooth transition from one board to the next.

SIDE NOTE: The much more expensive, 2" thick composite sold for railing cap would have stuck up above the thicker granite, creating a problem in need of a solution, had I used it.

(1.3) In a pinch, I could have used more composite mounted atop the supports. Better yet, I could have bought some of the thicker railing cap composite material, installed 90-degrees to the runs of composite. That would have required cutting 45-degree angles on each end, then gluing pieces cut from scraps of the same material over the exposed ends. However, because I could, I stayed with granite.

(2.0) Installing caps over the braces and that reach far enough back to cover where the brace attached to the deck required caps six inches (6") wide and about twenty inches (20") long laid 90-degrees to the railing caps (see photos).

(2.1) For the ends that didn't need the longer pieces, over the existing, doubled up 2x4 posts, I cut six inch (6") x six inch (6") squares. For my deck, that was 13 matching square caps to cover stair ends, points where the composite cap terminated and no brace cover was used, and point where the composite made a 90-degree turn.

(3.0) Cutting, rounding edges, and polishing granite is easier than it might appear. However, it does require care, attention to safety (e.g., GFI circuit for power tools, safety glasses, ear protection and protection from mist and dust), and patience.

(3.1) Granite and stone can be worked with common tools many of us already have. For example, a circular saw and an angle grinder.

(3.2) On the matter of patience, just as with woodwork, you must work through the polishing grits. That is, remove all the grinding/sanding/polishing marks from the previous grit, before moving to the next. If you don't, you'll spend hours longer, wear down the equipment and, in some instances, have to back up and start over.

(3.3) As indicated in the TOOLS section, you will have to buy a diamond blade for the saw (a Harbor Freight one will do fine for the grinder), a hook and loop pad for the polishing pads, and the diamond polishing disks for the grinder. If you want more rounded edges (i.e., "bull nose"), you'll want to consider buying one of the grinding stones used to rough in rounded edges. They're big, but they are surprisingly cheap, for what you get. And get a lot of roughing in done quickly using these stones. And, if you want more extreme rounded edges, consider the diamond router bits that screw on to your angle grinder.

(3.4) Getting all the pieces cut, rounded over and polished took several hours of work, but the end result makes for some unique and striking deck railing.

(4.0) To create the granite brace and end caps/covers, I, first cut my scrap granite to 6" wide strips using my tile saw. When done, I squared up one end, if necessary.

(4.1) Once I had my six inch (6") wide pieces, I then to six (6) or twenty (20) inch lengths. That took some planning, because I wanted to use the more striking granite scraps for some areas, but I only had so much of a given flavor. For that reason, if the remaining scrap from a twenty inch (20") cut was long enough to make a 6" square cap, I saved it.

(4.2) Had I not owned a tile saw, I would have done as I did in the past, before I bought one - I'd have used my Makita circular saw, a guide clamped to the granite to assure straight cuts, and a 1/8" hose coming off an adapter connected to my regular hose and a control valve to cool the blade.

(5.0) With all cutting complete, I began polishing the edges. All the following was done using the same cool system I used on my circular saw. The cooling is critical, because it will make blades and polishing pads last MANY times longer than if you didn't cool them. Too, it helps stop the pads from loading up with dust and losing their polishing efficiency.

(5.1) In working the edges, I slightly round them over, rather than doing a major round-over, like would be done using my 1/2" or 3/4" round-over diamond router bits, or, in a pinch, the grind stones.

(5.2) I started with a 50 grit diamond pad, taking care to keep constantly moving and rolling the grinder-polisher back and forth between side and top. I paid a great deal of attention to avoiding allowing the pad to come flat against polished tops and sides. To help, you could add painters tape to the clean, dry granite, until you get the hang of avoiding making more work for yourself, or detracting from the finished project.

(5.3) MY tile saw cuts were smooth enough I was able to start my polishing processes using the 100 grit diamond pad, then moving through these grits, WITHOUT SKIPPING one: 200, 400, 800, 1,000, 1,500, 2,000 then 3,000.

(5.4) As with a wood or paint sanding operation, trying to skip a grit ends up taking longer than if you'd used it. In fact, it can be worse, because you may have to drop all the way back to, for example, 100 or 200 and work your way through again (you can guess how I know). It's important to remove all the sanding marks from the previous grit, before moving to the next. Because that can be hard to determine, working with wet granite, I just make it as point to allot enough time to insure I removed the scratches. For my pieces, that was about 7 minutes for a side. Your time WILL vary.

(6.1) To install the the caps/covers over the railing braces, I had to build supports on which to lay them. For that, I used 2x4's. The finished braces, that lack side covers, until I decide how I want to cover them, can be seen in the photos. They are about two inches (2") shorter than the distance from the deck railing to where the stabilizing brace attached to the decking, and the granite caps, that are, also, about 2" wider than the supports, to limit how much rain and snow would affect them.

(6.2) If you don't butt the composite against granite and, instead, use composite, you'll need to make 45 degree cuts on any visible ends, then add what are called returns, in the molding installation world. These 45-degree ends get glued to ends of the 45-degree end cut to hide the composite material. These are made using scraps from other cuts.

(6.3) Regarding the supports, all that is left for me to do now is, decide how I want to cover the sides of the braces supporting the granite caps over them. I've toyed with using cedar from pieces of fencing I ran through my band saw (so just under 3/8" thick pieces), or just going with metal.

(6.4) As to the conduit, I could pretend I don't see it. On the other hand, I've considered using square vinyl down-spouts that have angle cuts on the ends to match the conduit braces. A section cut out of the back would allow me to fit the down-spout material over the conduit without removing it. Then there is that common 2" PVC might fight the bill for some. Either would take latex or acrylic paint just fine. Schools still out, for now.

(1.) With the railing movement problem solved, I tackled the rail cap issue. Since I was going to a lot of effort to repair the railing and add to its appearance, I wanted to insure it would last as long as possible. Research suggested the best way to do that was, use composite, instead of wood.

(1.2) Going down the composite road, the first problem I ran into was, all the railing cap boards every composite company sold was 2" thick, by 6" wide, 12' long, and ran around $200.00 each. Factoring in the standard 10% waste figure, that pushed the cost of the cap for the railing and stairs to around $3,000.00.

(1.3) In stark contrast with 2" thick railing cap prices, regular decking boards only ran about $45.00 per 12' board, and I could get longer boards for a bit more. That's more than $2,000.00 in materials savings, just for the composite railing caps.

(1.4) Using the two inch (2") composite rail caps would have created different problems:

(a) The shorter boards would have required me to butt the boards together (actually, with about a 1/8" gap);

(b) I would have had to add more post caps, because of the short lengths of the cap boards; and/or

(c) Because the two-inch (2") thick composite boards are thicker than the, approximately, one and one quarter inch (1-1/4") thick granite, I would have had to build the above described returns on each spot where the composite butted against the granite.

(2.0) With the decision made to use decking for the cap, I had to get creative with how I attached the cap. Decking boards are only around 1" thick, so there isn't much room for error, when running screws in to the bottoms of the boards.

(2.1) I didn't want to compromise the appearance of the cap by drilling holes through it and securing it with screws. I was no less concerned with that I didn't want to do anything that might compromise the longevity of the composite, such as might happen if water were allowed into the composite via mounting holes in the top.

(2.2) I searched the Net, but could not find any professionals or amateurs who used one inch (1") composite decking for railing cap. Accordingly, there were no instructions, or solutions, on how to do it. For that reason, I had to devise my own method of securing the one-inch composite caps to the 2x4 support under them.

(2.3) In the end, the solution was less problematic than I feared. It involved taking a lesson from the world of table building, which uses exaggerated Z shaped clips to secure table-tops to the supporting apron (sides). This is done by slipping the clips into a shallow kerf in the apron (those on-edge boards that are at the outer edges of your table-top), and screwing the other side to the underside of the top. This allows the wood to move with changes in the moisture content, while still securing the top to the apron, connected 90-degrees to it.

(2.4) I bought the clips in bulk on-line. I bought enough to install a clip about every 12" and on both sides and to allow for dropping a few here and there too (which I did).

(2.5) Since the railing was already built, the 2x4 support under the cap was in place, and did not require replacing, so I needed a way to put kerfs like slots in it, without it becoming a major project (e.g., removing and re-installing the horizontal support 2x's).

(2.6) To solve the problem of creating the needed kerfs/slots for the clips slip, I looked to my biscuit machine (see first tool photo), which is used to make slots on two pieces of wood into which you fit a chosen size of wood fiber biscuits. You add glue, then join two pieces of wood.

(2.7) After a simple set up (adjustments and a few test cuts on scraps), using the biscuit machine to make slots every10" to 12" inches, on both sides, went fairly quick and with little effort. I was even able to do the kerfs/slots on the outside of the railing from the deck.

(2.8) Once all the slots were cut, it was just a matter of laying composite boards I'd cut to length, allowing about 1/8" gap on each end, where the boards butted up to a piece of granite, on the railing cap supports, clamping it in place, then installing the Z clips.

SIDE NOTE: I buy screws in bulk. In part because I have the room to store them, and because I've found I can get hundreds more for just a few dollars more. Too, I try to stay with square drive heads, because they are far less likely to strip, and will, usually, stay on the end of the driver bit to get them started.

(2.9) To install the Z clips, I tried #6 square drive screws that are 5/8" long. That length left zero danger of piercing the tops of the composite boards. That aside, I dropped a lot of the #6 screws, and suffered a lot of finger pinches, trying to get them started. I switched to #8 square drive screws 5/8" long and the installation of the clips became a breeze.

(3.0) Once all the cap and rail was in place, I used blue painters tape on the composite and granite, where they met, to allow me to caulk all the joints without creating a horrible mess.

SIDE NOTE: As mentioned, it pays to use a good quality, elastomeric caulk, for its durability and flexibility. Even then, a week or a month in, you'll have to come back and touch these areas up again.

(3.1) I, also, caulked all the kerfs/slots the Z clips mounted into, and everywhere the composite cap laid on the support under it. This both increased the soundness of the attachment between the cap and support, it made for a much better looking end result.

(3.2) The final touch was, to use the same paint used to paint the railing to paint over all the clips and caulking under the rail caps.

(4.0) All this is a LOT of work. However, it feels fantastic to look at the end product of your labors, see a really nice looking rail system unlike any others, and that would have cost THOUSANDS UPON THOUSANDS of dollars, if you'd contracted with someone to do this for you.

SIDE NOTE: Just the granite for my project would have cost as much $2,000.00, or more. Add to that, the over $2,000.00 I saved using decking, instead of rail cap. Finally, figure at least $3,000.00 for all the other labor described above.

The cost could be higher if you relied on certain "experts," many of whom, likely, would have insisted you needed all new railing, and who would not have known how to use the Z clips to install the composite caps.

In the end, our rail repair would have cost going on as much as $8,000.00, or more. By putting in the time and effort, we got it all for around $1,500.00.