16 Deck and Patio Ailments (and How to Fix Them)
When something goes wrong with your deck or patio, should you attempt a DIY fix or call a pro? We’ll help you diagnose your deck and patio disorders and determine the best remedy.
If you’re starting to see signs of wear and tear — or outright trouble — on your deck or patio, what should your next step be? As a general guideline, says Mitch Kalamian, owner of Solena Landscape Co., cosmetic damage can be a DIY fix, but structural damage generally requires the advice and skills of a professional to correct. “If you start with construction done properly in the first place, you’re a lot less likely to have issues,” he says. “But if that isn’t the case, paying for professional expertise is always advisable.”
Here’s our advice for some common problems you may experience, starting with hardscaping:
Stone and Concrete Patios
Dirty or moldy surface. This is one fix you can perform yourself, and it may be as simple as a scrub with mild detergent. But if you have a stubborn mold problem — say, if your patio receives mostly shade — Kalamian recommends pressure washing first, then getting down on your hands and knees to sponge the surface with a very dilute mixture of muriatic acid and water. (Muriatic acid is available at hardware stores or pool supply stores; be sure to wear gloves and safety glasses as you work.) A final pressure wash when you’re done should leave you with a bright, clean surface.
Broken, uneven or sunken pavers. In general, call a pro. Man-made pavers are typically installed on a base of gravel and sand, and although it’s fairly easy for a professional to reinstall that base to correct undulation, Kalamian says, it’s much less so for a homeowner unless you’re experienced. Got just a single broken paver you’d like to replace or want to tackle the whole job yourself?
Weeds in joints. Fix it yourself. “Keep a handle on weeds because once they get out of control, it becomes a big job,” Kalamian says. Keep your patio swept free of dirt buildup that can harbor seeds, and pull any weeds you see immediately. A caveat: if the same weeds keep coming back, resist the urge to pull and use a glyphosate herbicidal spray instead, which kills the roots via contact with the leaves. After the weed is nice and brown, then you’re cleared to pull it up. Also, consider replacing plain sand joints with polymeric sand, which hardens into a cement-like mix where weeds can’t grow.
Hairline cracks in concrete. Leave it alone. “A hairline crack is acceptable by industry standards — it’s an aesthetic problem only,” Kalamian says. “It’s a really tough thing to fix. You could put grout or cement in the crack yourself, but it won’t look great.” Plus, there’s a reason the concrete was stressed in that spot in the first place, so any fix you attempt probably won’t last.
Heaved concrete. Call a pro. “Concrete shouldn’t heave,” Kalamian says. “If your patio is heaving, there’s definitely an issue, and removing it is the only option.” Although it’s technically possible to replace a small section that has been damaged, it won’t match the old section, and you won’t resolve the underlying problem.
Brick mortar popping out. Fix it yourself, but know it might be a temporary solution. Brick is typically laid on a base of concrete, and broken or missing mortar may indicate that the base is compromised and needs to be redone. If you elect to repair it yourself, be sure to clean the patio thoroughly first so that you can accurately match sand colors for your new batch of mortar.
Lime or mineral deposits. Fix them yourself. Concrete is porous and can be prone to staining (say, from minerals deposited when you water potted plants) but also frequently releases a whitish film known as efflorescence that comes from water trapped inside. To clean, power wash or use the same muriatic acid solution described above; don’t use bleach or commercial lime cleaners, which aren’t intended for concrete surfaces. If you want to prevent efflorescence from recurring, “you need to reseal every two years like clockwork,” Kalamian says.
Grease stains. Fix them yourself. Kalamian recommends using a standard over-the-counter grease remover from your local hardware store — but know that if you’ve allowed a stain to sit too long, it’s probably not coming out.
Fixing isolated problems, like replacing a single bad board, is something you can do yourself, but leave structural problems to the pros.
Peeling or faded sealant. Fix it yourself, and do it promptly (every two years is a good rule of thumb) so that all the wood is evenly protected. Get step-by-step instructions on this project here.
Moss and lichen growth. Fix it yourself, via power washing, to avoid slippery walking surfaces, but be careful not to use too much pressure. (If you aren’t sure of what you’re doing and don’t want to risk damaging your deck, it’s perfectly acceptable to call a pro for this job.) Overzealous power washing can scratch up the surface of the wood, inviting even more growth over time.
Missing, warped or cracked boards. Fix these yourself, as long as the problem is small. “If you can isolate the problem, you can solve it,” Kalamian says — meaning, if you can add a new fastener or two, or replace some damaged boards, and the deck is good to go with no leaning or swaying, you’re good. But if small fixes don’t eliminate movement, get a contractor to take a look.
Spongy decking underfoot. Call a pro. If the problem is widespread enough that it can’t be corrected by replacing a few boards, you’re looking at a real safety hazard that requires professional attention.
Swaying or leaning. Ditto. “Unless your deck is six inches off the ground, there are very few instances where you should tackle this on your own,” Kalamian says. Even if the problem can be fixed — by installing angle bracing, for example — you need a professional to determine whether repair or replacement is in order.
Wobbly, undersized or rotten posts. Call a pro. If your posts are an isolated problem and the deck is in otherwise good shape, you may be able to repair the posts rather than replace the entire deck, but shoring up the deck properly so it doesn’t collapse while you’re working requires experience.
Rotting or missing ledgerboard. Get professional help for any problems with the deck’s point of attachment to the house, which is critical to its stability. “There are endless issues involving the ledgerboard — bolts rusting through, insufficient bolting, moisture — but a homeowner doesn’t necessarily know what to look for,” Kalamian says. “Sometimes it should be dismantled, or sometimes you can simply replace it or bolt it properly, but that’s a pro’s call.”
Wobbly railing or stairs. If your handrails or steps wobble or lean under pressure, consult a professional ASAP, even if you think the problem looks simple to fix. It’s a safety issue that must be handled according to building codes.
DO seal your wooden deck every few years.
Save yourself some hassle and choose a one-step product that combines stain and sealer. Mitch Kalamian, owner of Solena Landscape Co., recommends Behr’s All-in-One Wood Finish for a good-looking, durable final product.
DON’T sand your wooden deck before sealing unless it’s really necessary.
This step is only a good idea if your deck’s surface has become too rough for comfort, because it adds several steps to your finishing process. “Sanding strips off that top layer of stain, so to do things the right way, you’ll need to put on three coats of stain and sealer afterward rather than just one,” Kalamian says.
DON’T paint your deck if you can help it.
“Priming and painting is always a two-step process, and any moisture trapped underneath will come through at some point,” Kalamian says. “Painting wood creates maintenance that you absolutely must do no matter what.” Where a stain simply fades — and can be replaced as needed with one coat of the right product — paint will chip and flake and is a pain to redo.
DON’T feel obligated to seal your patio.
“If you want a wet look all the time, then seal your hardscape,” Kalamian says. “But you’re creating maintenance, because you’ll have to reseal your patio every two years like clockwork.” Natural materials like slate and bluestone actually tend to self-seal under foot traffic and don’t need the extra layer of protection unless you simply like the glossy aesthetic.
DON’T go overboard washing your deck.
“You want to wash regularly, but not too regularly,” Kalamian says. Normal wear and tear plus constant pounding by the sun’s UV rays takes its toll on the wood’s surface, and if you scrub or power wash too forcefully — or even just wash with water too often — you can actually cause further damage. Plus, if you live in a damp climate, introducing too much moisture into the wood can lead to warping and splitting. Wash only when there’s visible grime, stick to plain water from a hose when possible, and save power washing for every few years during the sealing process.
DON’T overdo washing a stone patio, either.
Natural stone tends to flake, and overzealous washing can actually wear the surface away. It’s best to wash as needed rather than on a regular schedule. Use a mild household detergent occasionally if you see heavy grime or stains; stubborn stains and mildew can be removed with a very dilute mix of muriatic acid and water. (Muriatic acid is available at hardware, big-box or pool-supply stores; be sure to wear protective gear as you work with it.)
DO be careful with power washing.
Too much pressure can damage wood and stone surfaces. “Pressure washing should be done by an experienced hand,” Kalamian says. “If you’re savvy, you can do it yourself, but you might make some mistakes the first time. A guy that does it every single day knows how much pressure is too much.” To be safe, Kalamian recommends hiring a licensed, bonded, insured pro to do your power washing—and be sure to seal your wooden deck right afterward.
DON’T get harsh cleaners on nearby plants.
When you’re absorbed in getting your deck in tip-top shape, it’s easy to forget that your garden plants are in the line of fire. “Don’t hose muriatic acid off into plantings unless your solution is very dilute,” Kalamian says. If you have a lush landscape near your deck, drape plantings with a sheet as you work and choose the mildest cleaning solution first — say, dish soap or baking soda — before you try harsher chemicals. (Remember that plants’ roots are sensitive as well as the leaves, so anything you hose off onto the ground can affect their health.)
DO fix nail pops, split wood and missing boards promptly.
“If your deck was installed properly, you shouldn’t have a whole lot of that going on,” Kalamian says. “But wood expands and contracts as it ages, so anywhere there’s a span of wood, like a handrail or floorboard, you might get some creaking or something coming loose.” Screw everything down properly and sand any sharp splinters as soon as you find them, as small problems have a way of becoming bigger problems over time.
DON’T worry about concrete imperfections.
“Hairline cracks are an acceptable industry standard,” Kalamian says. There’s no need to fix them — and trying to mend them with additional cement or grout usually looks worse than the crack itself. Same goes for the whitish film that often collects on the surface of concrete, known as efflorescence. It’s the natural migration of salts and moisture to the surface, and can be considered a harmless color variation rather than something you need to clean. But if yours is extreme or you just don’t like the look, power washing will remove it temporarily. Sealing is necessary if you want to stop it permanently, and will require a strict maintenance schedule.
DO install irrigation for potted plants.
A container garden is a wonderful thing for ambiance, but it can wreak havoc on your deck or patio’s surface. Overwatering leads to puddling, which leads to mold and stains caused by mineral buildup as the water evaporates. “Anytime we install a deck, we always use saucers for potted plants, connect the pots to an irrigation system, and install a drain tied into the below-ground drainage system whenever possible,” Kalamian says. “That way no water pools around the bottom or leaks across the deck.” Stains caused by pots often can’t be removed, so prevention is your best option.