How common is it to repair cracks above a boiler and hot water tank in a 1965 house, and what is the typical process for reinforcement?
Hey everyone! Just wondering if anyone has any insight on how to go about fixing this crack. We’re not exactly experts when it comes to DIY projects, so we may end up hiring someone to help out (although my dad is pretty handy!). We’re just curious about how common this issue is and what the typical process is for reinforcing a crack like this. It’s located above our boiler and hot water tank in the corner of our laundry room, so it’s a bit of a tight squeeze. The crack doesn’t go all the way to the top of the joist, and we haven’t noticed any other cracks on the same one or the neighboring joists. It kind of caught us by surprise since we hadn’t noticed it before!
The visible nail is actually from a piece of sloppy sheetrock the previous owners used to cover part of the ceiling. It ended up falling down, so we tossed it out. We’ve had to redo and fix a lot of improper DIY stuff since we moved in 4 years ago! Our house was built back in 1965.
Thanks for any advice or information you can share! 😊
Typically, you would take a second floor joist and position it next to the existing one. Use a jack to lift it into place, ensuring everything is aligned properly, then secure both joists together. This has worked well for me in the past, but there may be other methods out there.
I’d recommend sistering it with another board of the same width, as long as it fits in the narrow space. Apply adhesive between the boards and screw them together. Saw a picture on Google for a visual.
Hey, mentioned that the wood isn’t rotted as some may think. It’s actually cracked near that huge knot on the right. This picture shows the best way to go – if you can access behind the ductwork, it’s best to run it through the other side.
‘s use of the double joist hanger is a great idea and really adds a lot of strength. I think it’s definitely the way to go.
I’m thinking about sandwiching it with some glue and bolts, maybe even.
Here’s the perfect solution. It’s no problem at all!
This is the method – just ensure you use structural screws. Drywall or general-purpose screws are not suitable for shear. Bolts are also effective.
Simply reinforce it with another 2×6, apply liquid nails on the side and top, and secure it with plenty of nails. It should work well.
Personally, I’d start by using a jack to raise the area where the crack is located in order to bring both parts closer together. Purchase a piece of 2x stock that matches the height of your joist (like 2×8 or 2×10) in an 8-foot length. Attach the new piece to the old joist, running 4 feet on each side of the center of the cracked section. Secure it to the old joist using 3-inch drywall screws placed around every 16 inches, with one screw high and one low. That should do the trick
You nailed everything except for the drywall screw part haha. I’d start with adhesive first, then go for some lag bolts with washers. 
Yep, definitely use some lag bolts instead of the drywall screws
Ph Civitello remember to drill pilot holes to avoid cracking anything else haha 
How about this ⬆️
Jack failing piece
Use wood glue or construction adhesive
Attach a 2 by 8 or 2 by 10 on both sides, I like to go all out like that
Secure with lag bolts and washers
Remove Jack
Also, make sure to check the level upstairs, it might have sagged a bit…
Ph Civitello hey, try alternating a forward wwwwww pattern with an upside-down wwwwww pattern on the other side using 16 framing nails. Plywood might work better though
I’d use epoxy glue to secure it in place, then drill a vertical hole and screw it in while the glue is still wet. After letting it cure for about a month, I’d remove the jack and see that it’s now even stronger than before. While sistering is a good suggestion, I think it might be a bit too much. If the span is longer than 12 feet, then I’d consider sistering.
Hey , did you check out all the pictures? This seems like more than just a glue project. It’s located near the HW heater, and I’m guessing the bathroom is close by above. While it may not affect the structural integrity of the house, it appears to be related to a flooring issue.
Hey James, I’d probably refer to it as screw and glue. I also mentioned the option of sistering. Since we don’t have the span, we can’t determine the load capacity of that joist without significant deflection. Synergy is important in a structure where most elements are still intact and can create a greater whole. Your point is valid.
That joist has completely failed and needs sistering. You’ll have to jack it up to its original position and secure another piece of lumber of the same size or larger to the original joist. It’s ideal for the new piece to be the same length as the existing joist, but that might not always be feasible due to existing HVAC runs, etc. That’s the basic idea, but there are additional factors to consider like which fasteners to use, what kind of adhesive to use, the correct fastener pattern, etc. There are plenty of detailed guides on YouTube. I had to repair a few of my joists a couple of months ago, and one of them was cracked just as badly as yours. This was the end result after the repair.
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Our situation seems to be quite similar. I wish we had full access to the entire length of the joist, but unfortunately, it’s blocked by a boiler system and hot water tank. I can only reach about 3 feet on each side of the crack.
It’s not the perfect solution, but it might be the best option for now. You might consider adding extra support on both sides to make it even stronger. Just make sure to stagger the placement of your fasteners.
That massive knot should have led to the rejection of this joist during the construction of the house. However, can you reach the wall where this joist is connected? Do you have photos of both ends of this joist? Where it’s being supported? I suggest fixing the crack with glue, using a 6-ton bottle jack to lift this joist back into place along with a new one you’ll attach. Secure it with joist hangers on the ends and nail it down.
Is spot on about that faulty piece of lumber.
I would generously apply wood glue (titebind 3) into the crack, then use a bottle jack to close and hold it for at least 24 hours to let the glue bond. While it’s drying, follow the advice of others and attach another 2 by whatever to the side. Secure with adhesive, framing nails, or structural screws. Drywall screws should not be used as they are not meant for structural purposes and cannot provide the necessary tension or shear loads to firmly attach the new wood piece to the old one. Opt for the longest sister length possible. The break most likely occurred due to a large knot in the area rather than excessive load above.
For a basic sister joint, the new board should extend 4 feet on either side of the crack. Apply construction adhesive between the new and old boards, as well as strong glue in the crack. Lift both boards with a jack, then secure them with Simpson Strong screws from both sides in a staggered pattern every 6 inches.
Attach another one to it, sister.
Is definitely someone who knows their stuff. Sistering is definitely the solution.
Absolutely, there’s no requirement to cut anything out.
And avoid using drywall screws… haha
I’m relieved that someone like finally mentioned it
We’re currently laughing while hanging drywall on the floor joists
Screws for construction use
It’s recommended to go with structural screws or lags. They have a higher shear rating
I mean drywall screws are really just meant for securing kitchen cabinets 😂
But make sure to paint them first :p
It stretches all the way down, it’s just not split at the top.
Find a piece that’s the same size, drill 4 holes in it. Push it into place and then secure it with big bolts and nuts.
Place a couple of jacks under a temporary beam and raise them until it becomes taut again. Then, secure 3/4x 9 ” strips of plywood on both sides using a staple gun before slowly lowering the jacks back down.
Mentioned using a staplegun, but I would suggest using construction adhesive between the plywood (not OSB) and either screws or nails, not staples. Consider using the original 2×10 or similar boards on one side.
Screws lack sheer strength, while nails will likely cause damage. Use 2-inch long galvanized 7/16 crown staples with adhesive instead.
The best option is to remove the rotted board and replace it with a new one. Attaching new boards to a rotten one will only cause the new boards to rot as well. Prevent the moisture.
I don’t see any rotten boards in that area
Maybe it’s best to take a break from talking. This joist needs to be leveled, as mentioned, with sistering on at least one side, but both sides would be even better with the longest span possible. Use carriage bolts and Pl to secure them and combine them into a single joist. Staples are not at all reliable for anything structural 😂🙄
Where you are, staples might not be as popular as they are here, but we swear by them for sheathing houses. We cover every inch on the outside and every four in the field. Some houses have different methods, but sistering could be a temporary fix. What I suggested would definitely work better. Instead of messing with the old one, just get a new lvl and replace it. It might be best to cut the rim joist from outside and use a sledgehammer to fit the new lvl in, if removing the siding is easy. Kind of like how I handle your mom after taking off her panties
Do you happen to know what PL stands for?
I think there are screws specifically made for that kind of job. What do you mean by saying that ‘nails will blow that b___ apart’? If the joist cracked due to rot, the root cause of the rot needs to be addressed, even though it doesn’t seem like rot.
If you’re under the impression that using two 2x10s and stapling them together is stronger than gluing and bolting the piece as one, then I’m not sure there’s much anyone can do to convince you otherwise.
Maybe leave the tool work to someone else. If you think stapling sheathing is equivalent to securing a structural element, you might want to reconsider.
Recommends construction adhesive
Structural screws work great for sistering in this situation. They offer the same shear strength as nails. Staples just won’t cut it
Elias Smith I didn’t mean to imply it was damp or spoiled.
Elias Smith No problem.
Did you really think that comment was okay?
Thanks! I’ve been a bit out of the loop. I previously used Liquid Nails.
Do you know that screws have no shear strength? Are you using drywall screws?
Noticed that the joist cracked due to a large knot – a point of weakness.
Really? That’s spontaneous!
You should use 3/4 inch plywood strips that are cut to 9 inches and place them on both sides with staples. Do not staple 3 2x10s together.
Typically uses 3 inch screws with a t25.
But those screws can be easily broken as they don’t bend easily; they lack shear strength like most screws. You could try hitting them with a hammer and they will bend over and break.
There are plenty of screws with high shear strength. Just make sure you choose the correct ones. Just because some screws may be more prone to breaking than nails/staples doesn’t mean they lack sufficient shear strength. It’s important to use the appropriate screws with the right spacing, similar to nails. I have never come across staples being used to connect structural beams. Typically, it’s bolts, screws, or nails. I’m not ruling out the possibility, but it doesn’t seem very common.
We should definitely replace that beat. It’s not something you can fix yourself.
I’m not sure if you’re familiar with the term ‘sistered’. If not, it means attaching a new joist to an existing one to provide additional support. This can be done with nails or lag bolts, and the new joist will help carry the load of the damaged one.
Hey and , this is the way to do it! I don’t know where some of these people are getting their information, but 99% of them are wrong. To fix it, raise both or one side of the joist and use some grk or spax lag bolts that are 4 inches long to attach a 2×6/2×8/2×10, depending on the existing size, to both sides of the joist. Extend it 4 feet past the crack on both sides with an 8-foot board that you can easily find at your local hardware store. You can use 3″ nails or screws on both sides, making sure to space them every 16″ and use 3 nails/screws vertically for a 2×6, 4 for a 2×8, and so on. If you opt for lag bolts, use 2 at 16″ spacing for a 2x
Check out this article by on making structural repairs by sistering floor joists: https://www.familyhandyman.com/project/how-to-make-structural-repairs-by-sistering-floor-joists/
First, you should figure out why it’s broken – whether it’s due to fungus, mold, or wood rot. The key is to prevent moisture from causing further damage.
Clearly, there’s a huge knot in the joist already. That piece should have been utilized as blocking somewhere, no framer I’m familiar with would have included that in the floor system, without at least adding another 8’ joist right next to it centered on the knot
Backed off from tying knots.
You know, I don’t think we use 2×10 for floor joists anymore. At least not where I live. We haven’t done that since like the 50s.
You know, I never mentioned dimensions besides 8 feet in my comment in reply to yours. It really depends on the span and spacing of the joists. I do this professionally, not just as a DIY project. My aim is to assist, not just throw random information out there like you are doing. Anyone with experience can quickly see that there is little to no moisture present and the problem is actually due to a knot that was never structural to begin with. 🤷🏻♂️
Hey there!
The crack in the board just has random mycelium growing on it and the black and white stuff is what?? Maybe if you do this for a living you should understand how fungus works. It’s been around longer than us and it feeds on decaying plant matter. For some reason, we build our homes from plant matter. When you have a water heater in a cold basement, condensation occurs. Aka moisture. Black mold, dry rot, wood rot.
Bro what are you talking about, how many houses have you been to? Renovated? Built? There’s always random stuff, that wood is not damp. Yes bacteria/mold/mycelium can be present and feed on the organic matter, but that’s not the main issue here. Thousands of heat and cold cycles, along with living in a humid climate, can cause this sort of thing after getting drier in the winter. Take it easy, any of my restoration companies would dismiss those dots as nothing. Real-life experience is more valuable than just reading things and zooming in on a picture. Keep going and arguing, but I’ve been around the block a few times and provided a real solution to their problem. If there was actual moisture, there would be more than dime-sized spots, and a leak/condensation/mild moisture like that wouldn’t crack the wood like in this case. There’s a massive knot, if I jumped on that joist before it was installed it would’ve snapped either way. 🫡🤷🏻♂️
+++ Looks like there was drywall on there at some point. The white could be from demo and drywall smacking the joist. There are various reasons for the black, iron reaction with elements in the air, tar from a roofer walking on it, or it being a lumber pack etc. It doesn’t look like mold to me. Old insulation has a tar backing which could transfer to the wood from time to time.
In this basement, there’s a lack of proper ventilation due to old construction. Mold and fungus spores were just waiting for the right moment to thrive. The old materials and lack of proper seals are causing a cycle of problems.
This basement has heat and is finished. I managed to remove whatever you circled.
Hey, don’t listen to that guy. He really doesn’t know what he’s talking about. The joist failed due to high traffic and extra weight, not a moisture issue. Plus, there was already a knot weakening the wood from the beginning.
Pin it up with a jack first, then apply glue and screws to 3/4 CDX (not OSB) on both sides. Cut it to the required size. Aim to utilize the entire 8ft length, including the crack in the middle. Make sure to use PL Premium glue
Absolutely not. No signs of rot or decay found on the joist or subfloor above
I recently completed a sistering project in my bathroom above the basement. While I didn’t encounter any joist problems, I needed a solid surface for the sub-floor near the tub and toilet, so I added an additional joist.
If the joist is still in good condition, you can simply drive some screws into it to reinforce it and then attach another joist to the side for extra support. It’s a quick and easy solution
To sister a piece of lumber, simply place it next to the existing joist, clamp them together, and then secure them with screws or nails.
I appreciate all the helpful suggestions, but I think I’ll need to hire a professional for this job. There is a drop ceiling to the left that can be accessed, but it’s just too much for me to handle.
Give Dad a call, . He’ll be able to help you out. And don’t pay attention to that guy, Jason!
When you’re sistering a new joist, there are various fasteners you can choose from. However, 3-inch 10D nails are cost-effective and will get the job done effectively.
The crack appears to be coming from the knot. When selecting the ‘sister’ piece, ensure it has as straight of grain as possible.
This is it!
So, every now and then in these DIY groups, you come across some pretty passionate people who may not exactly know what they’re talking about. Sometimes they can really make you feel like you’re dealing with a major issue.
But hey Jenn, that’s not the situation here. Nobody is being extreme or blowing the problem out of proportion. Unfortunately, as mentioned, that joist can’t be fixed. It’s completely compromised. The crack runs all the way through, which is the worst spot for a compromise in a beam. As others have also pointed out, it will need to be reinforced. That’s ultimately the solution.
However, before you go ahead and do that, or have someone else do it, there are some important questions that need to be answered. First off, what is the span? Did the joist fail because it was supporting too much weight for too long? Also, rather than focusing on what’s underneath, what’s happening above that joist? How much weight is being placed on it? Is there a major load-bearing wall adding extra weight that it wasn’t originally designed for? Have any renovations been done that have increased the load? And finally, how much support does the joist have at either end?
These are the questions that, given the seriousness of this structural issue, you should consult a professional about. In the meantime, it would be wise to provide some temporary support underneath it. Even if it means placing a beam across with two supports (avoid using single 2×4’s as they may bend). But definitely have a professional assess the situation and advise you on the best course of action moving forward!
Hey , it seems like the crack is due to the large knot in the wood, no need to overanalyze it.
Hey , do you think the joist is suitable for the span? What’s on top of it? What put so much pressure on the joist to make it crack, especially with another joist on each side? Yes, there’s a knot, but could a small deflection lead to complete failure? I believe it’s worth looking into further, even if it seems like the joist is weak.
Hey , are you a carpenter? I work in the trade. The crack didn’t happen just because of a knot. Small knots alone can’t cause that. And the joist doesn’t really have a severe knot. HOWEVER, the crack seems to go in a different direction from the strands around the knot. I think it might be due to a weight or support issue, and it cracked close to the knot because that’s where the strain would likely lead to. But the knot itself is not the main cause of the crack, at least from what I’ve seen.
It’s important not to overlook anything, especially when dealing with a significant investment like your home.
💯
Hey, I’m also in the trade. Not that it makes us superheroes or anything, but yeah. The crack happened because of the knot. It’s not a small knot at all. Surprisingly, it’s not even drooping. There’s not much weight on it. Things shift and change, and a knot like that can often lead to splitting. You’re suggesting that someone should shell out a few grand for a structural expert for something quite simple.
Replace it
Put a second joist next to it to replace it. It seems like it was weak from the beginning, but make sure to check the load above it.
As many people have mentioned, the best way to properly fix this is by adding a new joist next to the damaged one of the same length. Using construction adhesive can help prevent squeaking, but it’s not really for structural support. Before doing anything, make sure to check what is exactly above the crack to avoid causing any other issues when lifting the floor. Sometimes, a sagging floor can lead to cracks in the walls or ceiling above, which may have been covered up with patching by previous owners. Be cautious as lifting the floor could potentially cause cracking or misalignment of doors upstairs. It’s always good to double-check before proceeding. I have dealt with mold growth before and I don’t see any signs of it here, but if you’re concerned, you can use a mold spray/inhibitor as a precaution. Personally, I don’t think it’s necessary. Additionally, there are special structural screws available for decks that can be used to secure the new joist in place. Best of luck!
Is located directly above the kitchen (where the refrigerator is).
I think she’s got the hang of sistering now… maybe limit the comments to avoid repeating the same answers
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I’ve found all the comments helpful because I’m new to resolving this issue. Even if they seem repetitive to others, I’ve learned a lot from reading them 😊
I actually believe that the dark substance is a plywood stamp though. Probably done by a plumber, not the traditional ones who soldered the copper lines, but the ones who used PVC pipes. It’s possible that in the past they used angled 1x over the floor joist. This was before plywood. They used large hand-driven nails to secure the floor joist. Perhaps in the 80s, there was a flood in the upstairs bathroom or the carpet rotted, leading to the removal of the old material and the use of plywood that we now see. It’s time for me to go to bed now. I’ve spent too much time using my vivid imagination on this. Jack up the section and replace it with an LVL beam after cutting it out. Purchase new pipe insulation for those pipes. Find a better way to secure the electrical wiring. Locate any air leaks, construct a drop ceiling with air seals around the return duct, cover everything neatly, apply liquid nails, attach rigid foam, tape the seams, and then secure drywall with screws to ensure the adhesive sets properly. For the remaining drywall, painting, and finishing touches, I would recommend hiring a professional and moving on to the next DIY project.
Jason, you really need to take a break. You’re overthinking things too much.
Here, hope you all have a good night. Just wanted to thank you for the laughs. And by the way, please don’t take me too seriously, especially the DIY folks.
The “old school plumber,” mentions that he frequently sweats copper, switches to pex, or fixes the mess left behind by previous plumbers. He prefers wirsboro pex from uponor for new builds and uses RHBG or clear pvc cement with purple primer for PVC pipes. ABS glue is black and there is no need to cut out a joist; instead, one can learn how to sister joists for a structural fix. He recommends R-30 insulation over rigid foam and advises against gluing drywall to a ceiling. For electrical work, he suggests using foil tape or duct tape instead of sealant. Jason recommends gaining experience by working with remodelers or contractors to learn more.
For this project, it is suggested to fill with glue (visit woodcraft and show them this image to get advice on the best one-part glue). Temporarily tape and predrill with a long 5/16 bit, making sure not to penetrate the floor above. Insert two screws to let the excess glue squeeze out. Remove the tape, wipe off any extra glue, and finally reinforce with a beam of the same size.
https://www.homedepot.com/p/GRK-Fasteners-3-8-in-x-8-in-RSS-Star-Drive-Washer-Head-Alternative-Lag-Screw-96020/204837527
If you have a 10 or 12” beam, consider purchasing a longer screw. It’s recommended to use an 18 volt impact driver to easily install these screws, which will come in handy for future home repairs.
In Australia, this is not a common occurrence. We mainly use hardwood, not to brag or anything. 😁
Encounters pain and death from insects, spiders, reptiles, and animals at every corner. 😂
It’s really not that terrible! 😄
Hey , I haven’t been bitten yet this week, but it’s not over yet.
Apply glue, lift it into place using a jack, and sandwich it between two boards with a few through bolts. This will create the strongest section of the floor.
Great suggestion, .
To repair the crack, consider gluing and screwing it shut. Then reinforce both sides with a 2×10 spanning about 6 feet (3 feet on each side of the crack). Nail it in a dice 5 pattern with nails spaced every 6 inches.
If you’re looking to hire someone, go for an experienced carpenter or even better, a millwright. They are in the same union but more precise. Just be prepared to pay 50 percent more per hour for the millwright since they do not receive overtime pay.
The beam is no good, it will require another one to be laminated onto it and bolted through, most likely needing to be propped up first to level it or straighten it out
I noticed a new piece of plywood up there. The color of the joist seems a bit off. Do you think there might be moisture causing issues?
It’s actually a pretty simple repair. Just grab a board of the same size and attach it as a sister. Secure it with nails or screws, then use ledger locks, staggering them every 16 inches on center. The only challenge might be if there are lots of wires or pipes running through it.
How about grabbing some 2×10 and attaching it as a scab or sister?
Little sister.
Oh my goodness! Such exaggeration! It’s not the end of the world. You don’t have to replace the entire joist. Raise the sag with a 4×4 cut slightly longer than the distance from the floor to the joist. Align it vertically using a sledgehammer, then take a 6-foot joist of the same thickness, glue it with liquid nails, and secure it with 16d nails in a diamond pattern. That’s all you need to do! Your house won’t collapse! Goodness gracious!
Maybe you could have left out the harsh attitude in your response…..
Huh?
Who am I supposedly berating? I’m just trying to offer some words of hope and support.
It’s not as daunting as some people are making it out to be, scaring off the person asking the question.
You’re reading too much into it, I didn’t mean any harm.
Thanks, I totally get what you mean. I’m pretty new to homeownership and never faced anything like this, so I’m kind of at a loss
It’s not exactly a walk in the park for someone who hasn’t tackled a project of this magnitude before, so I really appreciate your response
I don’t believe Joe was referring to you, but to those who mentioned that your house might collapse… like right now…
No way!
It’s always best to correct it according to the original plan.
So, what have you constructed, Chris?
Hey there! I appreciate that. I’m really just trying to share my 40 years of experience. Maybe I’ll just stay quiet and help boost the economy. 🥸
Hey, I actually did something similar a few months back with my rafter tie that splintered in the garage. I ended up jacking it, screwing the splinter, then gluing and nailing a scab alongside.
What’s the reason for your confrontational tone?
Improper DIY projects are quite common in any household. It’s usually not a big problem unless it affects the structural integrity of the home or the exterior.
The most effective method is to sister, which involves screwing another joist against the damaged one, ensuring it bears weight by resting on a supported wall or foundation
If it’s connected to a beam you would probably want to use a double joist hanger
To properly secure the joist, make sure to sister and anchor them together with structural screws every 8-12 inches along the center of the boards. The board should run the entire length between supporting sill plates.
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Hey Jason, maybe it’s time to take a break. When it comes to installing forced air furnaces and hot water tanks, it’s important to have a fresh air intake in the utility room for combustion. Hot water tanks are sealed and don’t create humidity. Not sure where you’re getting this talk about humidity and water damage…and staples? Maybe brush up on HVAC and framing codes before giving advice. Staples? Maybe grab a beer with a structural engineer instead. And maybe offer to pick up the tab, they might appreciate it.
Here’s an updated version of the text in a conversational tone:
So, what I would do is use adhesive in the crack and place a 2×4 in the center of the bottom edge (also with adhesive). Then I’d lift it up to make sure it’s level, screwing it to the bottom every 6-8 inches and 2 inches from each end. Next, I’d cut two pieces of 3/4″ plywood that reach 2 feet past each end of the crack and attach them on either side of the joist with liquid nails. Finally, I’d drill 1/2″ through bolts with nuts and washers, placing them 2 inches from the top and bottom leading up to the crack, and maybe adding one through the center of the repair.