Sagging kitchen floor

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Old 03-22-09, 11:33 AM
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Sagging kitchen floor

40 year old split level house. We've been in it 15 years but didn't notice this until we had an old addition removed & expanded and the kitchen redone where we pulled out the old vinyl flooring and countertop & replaced with a tile floor & silestone countertop. The addition was done 1st, later when the kitchen was pulled apart I noticed that around the sink area the floor sagged compared against the beginning of the addition. Maybe 2 inches at the worst part. Now we've noticed the floor tiles around the sink area coming loose. I'm thinking it's because the floor is sagging a little more with the extra weight of the new kitchen floor/countertop etc.

Below the kitchen is the basement - 8ft high with cinder blocks wall. Floor joists are 2x8 spaced 16 in apart running from the front yard to the back yard. They extend about 3 & 1/2 feet past the cinderblock wall. Above the kitchen is the attic.

Last summer I went in the crawlspace under the addition and underneath the part where the floor joists extend, I dug 3 holes in the center of the space, 4 feet apart and about 2 feet deep and fiiled them with concrete on which I put a pair of cement filled blocks and a pair of pressure treated 2x6s. Mainly for peace of mind to help keep it from sagging any further. But that area just stopped short of where the sink is where I notice the most sag. So I was thinking of going back under to do the same thing in the 6 foot span next to where I left off.

Is this doing any good to help prevent further sag?
 
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Old 03-24-09, 07:19 AM
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Since you have a basement under this section of the house I'd suggest installing some adjustable jacks with the screw heads on them so you can A: prevent further sagging & B: slowly over raise the floor bacl up to level. Post back if you need further guidance.
 
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Old 03-25-09, 08:15 AM
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Thanks for the reply,

The sagging area isn't under the basement, but under the cantilever area which is now enclosed by an addition. I have access to under the addition, but it's only about 2 feet high.

Since the kitchen/addition was redone, I'd be worried that jacking up the floor beams to level out that sag would also jack up the new kitchen countertop/base & wall cabinets. Since the countertop was installed level with shims, I'd wonder if jacking the floor up would "un-level" it.

I was thinking about trying to sister in additional 2x8's. I doubt they'd slide all the way into the cantilever area because of the bowing, but maybe I could get them indeep enough to help out some. I'm not really sure. Iwas also debating going underneath the addition and removing the thin layer of plywood that covers the bottom of th efloor beams as they extend past the basement foundation wall. I was thinking it be easier to slide inadditional 2x8's that way than going into the basement and sliding them (harder to lift it over pipes etc)
 
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Old 03-28-09, 11:14 AM
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Hi, csaag. Yes, the tiles are popping because the floor is still dropping. 2x8 joists, 16 on center are rated for 12 -8 span. You added the extra weight of the refrigerator, stove, plus any underlayment, the tile, as well as the countertop.

Did anyone do a deflection test on your floor joists before the floor was tiled? The cantilever at the kitchen wall is also supporting one half of the roof load, if trusses are above. If rafters are above, it depends on where your purlin supports are located. I would do a load test, evaluation, to see exactly where you stand.

The after-market piers are probably too small, or the soil may not be compacted, or stable enough to help. What thickness and weight underlayment was used? What type and weight is your tile? Does the refrigerator lineup with the sink floor joists? Or stove? How much does the counter-top weigh? What is the span of your trusses above? Did the plumber or anyone else notch any of the joists below? Did you attach any floor joists of the addition to the cantilever? Is any of the addition roof over-framing bearing on the roof over the kitchen?

Go into the crawl space under the house and site the top of the foundation wall for level, and the footing. I built many houses like this back in 75, and the codes were a lot more lenient then. Be safe, BGR
 
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Old 03-28-09, 02:08 PM
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Out of curiosity, did the remodelers attach your addition to the tails of the cantilever? It is not structural and the weight of the room itself is causing the sagging. There should have been a complete footing and foundation built to accommodate the weight of the cantilever and the new addition. Just a thought.
 
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Old 03-28-09, 05:27 PM
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The stove & frig are not on any part of the cantilever (in fact the basement has double 2x8's on the one beam where they sit). Just 10 ft of a silestone countertop, plus a sink & dishwasher and a standalone pantry and the cabinets above. The tiles are about 1 ft square; I guess they're normal thickness - don't know about the underlayment. The tiles just barely go under the base cabinets; they don't go all the way to the end of the kitchen (the part under the countertop that is).

I was told the prev owner built the old 10x20 addition after the house was built. It has it's own cinderblock foundation. I don't know how deep it goes. We had the old addition demolished but kept the foundation & subfloor (which is why we never the the sag in the cantilever). The beams that support it are all supported by that wall and a set of beams going down the center of the addition. So I don't think the house supports the addition. There is a beam attached to the back end of the cantilever that is also attached to the start of the addition, but the bottom of that beam shows level. Only a small portion of the addition roof sits on top of the house roof - just a few feet. The new addition is 20 x 20.

Today I went in the crawlspace and the old addition cinder block foundation runs under the cantilever. On one end the plywood that covers the bottom of the cantilever pretty snugly, but the other end has a gap that runs from 1 1/2 inches at the base and 1/2 inch at the end. I was thinking of filling that gap in with cement.

I dug a 4 ft level into the ground until it sat level and measured the distance from the top of the level to the plywood that covers the bottom of the cantilever beams. I measured it at the base , 1ft from it, 2 ft from it, 3 ft from it & at the end (41 inches from the wall). I did that for most of the joists. At the worst there was an inch gap, but most of the beams showed about a 3/4 in gap. Turns out I also used 2x8's, not 2x6's, for those piers I put under there last year.

QUES: I was thinking of sistering in 2x8's (about 10 ft long) in the basement. I could just try and hammer it in as deep as I can get it, but I don't want to force the floor up above and risk unleveling the countertop etc. But since I have an idea of the sag for those 41 inches past the end of the basement foundation, should I cut off a small triangular region from the top of each beam based on my measureemnts so I could get the joist all the way to the back of the cantilever?

thanks
 
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Old 04-02-09, 01:06 PM
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1. What is the exact measurement of the floor joists span? Not counting the cantilever.

2. Is the basement wall sagging? Go into the basement in front of the wall in question. In the left-hand corner at eye level, nail into the grout line of the block wall. Put another nail in the same grout line at the other corner. Hook a chalk line on both nails, 1/2 inch from the block wall, pulling it tight and tie. Check the area in question to see if it is sagged, or if it is level.

3. Is it possible to post a picture of the post to cantilever connection?

4. A 3 1/2 foot cantilever is very weak. Normally, maximum cantilever length is 24 inches.

Yes, I would put another 4 x 8 or six underneath the area in question at the cantilever. Resting on some posts, resting on a 18 x 18" x 8" footing. In addition, I would put a 24 x 24" x 8" thick footing underneath the beam that ties into the cantilever. Then I would cut the connection that joins the two. In addition, I would sister the house floor joists with another next to each one at the weak spot. I would cut a half-inch by bearing point length notch out of the width of the new joists at the bearing point locations. Shove them in while they are flat, tip them into place, put one half-inch plywood under the notched area for bearing. Nail them in place, two nails, 16 inches on center. Be safe, GBR
 
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Old 04-03-09, 07:07 AM
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I'll take a pic and post it tonight or tomorrow (if my son's talent show tonight makes me forget)

<1. What is the exact measurement of the floor joists span?

Are you asking the length from the basement post to the basement wall? I'll measure it exactly, but it's around 11 feet. Three 2x12's run across that post.

> 2. Is the basement wall sagging?
I don't believe so. When I was under the crawlspace last weekend I put a laser level on the near top of the basement wall and it measured level as best as I could measure it. (i.e distance from top of cinderbock to the cement line of the line of blocks under it)

>I would put a 24 x 24" x 8" thick footing underneath the beam that ties into the cantilever. Then I would cut the connection that joins the two

Not sure what you mean. I think you're talking about the support beams/footings I put under the cantilever.

<I would cut a half-inch by bearing point length notch out of the width of the new joists at the bearing point locations.

While I was under the crawlspace, I saw that the middle section of the cantilever had a half inch 8ft by 41inch sheet of plywood nailed to the bottom of the cantilever beams (the entire bottom is covered by the same, but the end sections have the plywood going over the old addition cinderblock wall which could make it problematic to remove)

I was thinking it be easier to slide the new joists in from the outside, as if I do it from the basement I have to lift them over pipes that run under the existing joists at the basement wall. There's also an occassional wire that runs thru the cantilever area and it'd be easier to workaround it that way. I would have to remove the 2x8's I put under there last year,but that's simple to remove and put back up.

Plus I could then nail the sister'd joists to the existing beams in the cantilever area which I can't really reach from inside the basement. I'd then cut a new half inch 8x4 sheet of plywood in half so I could get it thru the access hole and then screw it back in place. Then I'd leave myself an access panel between the 2 joists where the pipes to feed the kitchen faucet and the drain pipe are.

When I walk on the kitchen floor, nothing bounces, I hear no creaking of wood. Just the crackling of the tile glue. So I don't think it's any type of danger to try and pull off that plywood under the cantilever. But I could sister the beams from the basement.

QUES: how much does the type of wood used make a diff when sistering in - i.e pressure treated or non p.t. ?

Thank you for your time and advice. Much appreciated.
 

Last edited by csaag; 04-03-09 at 09:03 AM.
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Old 04-03-09, 04:04 PM
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1. The length of the 2x8 joists, from the back wall to the beam.

2. Set the laser level, measure the difference in height of the: A. bottom of joist at basement center beam, B. bottom of joist at middle of span, C. bottom of joist at back wall before cant.

3. "There is a beam attached to the back end of the cantilever that is also attached to the start of the addition, but the bottom of that beam shows level." Is that addition beam attached to the cantilever in any way?

4. The ply rips were put on only to hold insulation and help weather-proof the house and gaurd against critters (when it was outside - before the addition). No danger to remove, BUT leave any on that are still outside.

5. P.t. wood is not good for this application. Hold off untill you answer #1, and #2.

Be safe, GBR
 
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Old 04-03-09, 04:32 PM
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attempting to insert a picture, but it asks for a URL. Trying to link to photobucket. If the pic doesn't show then I listed the URL.

From the back wall to the support post in the basement is 11 ft.

I'll probably go back under the addition tomorrow and try a few pics from inside there.

Pictures by csaag - Photobucket

 
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Old 04-04-09, 02:45 PM
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Added a few more pics, some of the kitchen and some under the addition. Here's a link to all of them

Pictures by csaag - Photobucket

A) you'll notice the hole punched out in the basment wall from the shots under the addition. Last summer we had a smell in the sink area. Turns out the drain pipe from the sink (that went down into the cantilever and out into the basement before hooking into the sewer pipe) had a leak that was dumping water into the insulation that sat in the cantilever. To get the pipe out I had to cut a section out of the plywood covering the bottom of the beams in the cantilever. Even then we couldn't get the whole pipe into the basement, so we had to knock out a hole in one of the hollow sections of a cinderblock. We wanted the entire pipe intact to make it easier to properly size a replacement (which was done in PVC)
I doubt I'll ever have the problem again with the PVC and I'll leave a seperate piece of plywood between the joists around it so I can get back in there if ever needed. So I'll eventually fill in that hole.

B) One pic shows the plywood under the cantilever on the right side (in white) and the 1st floor joist for the addition on the left. The wood piece in the middle of them is a 2x4. To the right of that 2x4 was an insulation board. It had absorbed some of that waste water that leaked and settled in the back of the cantilever. So I used a long screwdriver to scrape out the rotten part and then bleached it. I don't know what the 2x4 is attached to. It doesn't seem to me that the addition is attached to the cantilever.

C) The floor joists in the basement between the center post and the backwall don't seem to show any sag when using a laser level or measuring from the bottom of the joists to the floor.

D) On the other pics under the addition, the support beams in the back is what I did. The ones running perpendicular toit are the original center support beams for the original addition
 
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Old 04-04-09, 05:34 PM
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The block wall on the addition was poorly done. Unless the plate on top was shimmed level.
You need someone more experienced to look at the situation. I feel the joists ,11' span------90 % of max, with the pantry, cabs., countertops, (all on the 42" overhang), are bowing the middels up. Middle up - cabs. down = tile pooping. Tile floor is the last straw, may be overloaded. Hire a pro, at least put rest of beam in at cantilever yourself. Are you having a problems with the double vapor barrier, or does that upper one breath?
Your pier can not do much good because the surface area is so small on the dirt. As posted before. Be safe, GBR
 
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Old 04-05-09, 06:58 AM
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When you say hire a pro - do you mean a structural engineer?
 
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Old 04-05-09, 12:06 PM
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I'm sorry I wasn't clear. Because of the extra loads on the floor, and the extra length on the cantilever joists, and the new addition's floor and foundation systems, I would recomend that you hire a professional, licensed Contractor to help. He would take measurments, level readings, pictures, and all pertinate information, to a Structural Engineer for evaluation, and solution. I feel this is more complicated than you understand, with all the factors considered. Be safe, GBR
 
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Old 04-05-09, 03:32 PM
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thank you again for your time and advice.
 
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Old 04-16-09, 04:16 PM
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Followup for anyone researching a similar issue - found someone to come out and inspect the area. I explaind the situation and he took some measurements in the kitchen/basement/attic and will let me know the short/long term impact of the deflection. I should know within the week.
 
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Old 04-29-09, 10:23 AM
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Turns out something will need to be done to support the end of the cantilever mainly for any additional load that could be put on the roof which bears on the end of the cantilever.

Since I live inthe northeast, snow & ice are always possibilities in the winter. Other than that, there wasn't a structural danger. Annoyances , yes, but real dangers, no. He tooka few more measurements and will get back to me with recommendations and we'll see ifit will require soem professional help to implement.
 
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Old 05-04-09, 05:46 PM
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The engineer's final report was that a load of snow/ice on the roof could overstress the beams. The weight issues added by the countertop was minimal. He said the sag (currently .5 to .75 inches) would double in 15 years from the effects of time alone. He recommends having a support built under the ends of the cantilever. He also said beams could be sistered in, but the best fix would be a support column (sistering could be skipped with just this). He gave me the name of a contractor with experience in these issues that he said was very good & reliable.

I may do the sistering myself. I already took care of moving electrical boxes, pipe hangers etc that were in the way of the beams that could be sistered. The engineer said to use wood that has a working stress of 850 lbs/inch. If I do, when I'm done I'll get an estimate for the work invovled in getting a support column under the cantilever.

QUESTION: Does anyone know if the type of wood I see at Home Depot/Lowes (Douglas Fir) meet sthese requirments?
 
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Old 05-05-09, 02:36 PM
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Found a book named 'Design Value for Joists & Rafters' that lists info like I need . According to it, Douglas Fir will meet the requirement for all types except the No. 3 grade. although I don't ever recall seeing any type of info on the wood at a Lowes/HD store
 
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Old 05-18-09, 01:32 PM
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Question for GBR (or anyone else that's read thru all this)

Currently I'm waiting to hear back from a contractor (from the engineer's rec) who came out to my house a week ago. They had mentioned that they had a long job soon and may not be able to take my job. But they haven't gotten back to me with an estimate so I'm starting to think they have lost interest.

I was thinking that the digging in the crawlspace part can't be a big plus for getting people interested. So last weekend I decided to go under there and dig out those old smallish piers I had put in.

The end result is that I have 4 circular holes, one each by the end walls the the other two roughly evenly spaced (20 foot span in total), that are 2 feet in diameter at the bottom, 3 feet in diameter at the top (only way to work in there was to start wide and narrow it as I dug down) and 2 feet deep. Two of the holes are a few inches deeper that.

Do you think that piers of that size would be sufficient to support a structure under the cantilever? I'm hoping that if I have to look elsewhere for contractors, that a big impediment to the job has been removed (or mostly removed).

thanks
 
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Old 05-18-09, 03:51 PM
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What size did the S.E. call out? That seems big and deep enough, as they are just helping stop the sag. It really depends on the load and soil conditions. May need to change everything.

What size and spacing did the S.E. call out? Should be on the paper you paid him for. Be safe, G
 
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Old 05-19-09, 04:32 AM
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That will come later. He wanted to see how the subfloor of the original addition tied to the kitchen. He had given me plans on taking up part of the new floor in the addition uin order to see the construction. The contractors had a copy of his plan and talked to me about that.

I had taken off one of the plywood covers on the bottom of the cantilever, and I reported to him what I saw from there. I'm waiting for him to get back to me on that. I've also sent him a message on the digging. We'll see...thanks
 
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Old 06-18-09, 09:07 AM
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To complete the story -

Contractors finished the job yesterday using the plans drawn up the the engineer. I had previously verified that there was a 3 ft footer under the cinder block foundation at either side of the cantilever, so they chisled out an area into the cinderblock on each side and dug one 3ft hole in the center. They were quite appreciative of the off-center holes I had dug as it allowed them more room to work under there, so they gave me a couple of hundred discount off the labor.

I forget the exact term they used (micro something) but the support beam they used looked like seven 2x3's glued together. It was pressure treated & quite heavy. They used another 4x4 pressure treated piece that was connected to something called a boot. This boot was bolted to the concrete pad. The 4x4 was inserted into it and the support beam fully sat on it. That 4x4was wider than the support beam so they notched it and bolted the support beam to the notched part.

They cut the plywood covering off the bottom of the cantilever so the support wood is firmly against the basement floor joists. It was also shimmed where necessary.

The pad used for the cantilever is right behind a seperate pad that was used to support the floor joists of the addition .The addition is 20 feet wide so this other pad had a pair of 2x8's going perpendicular to them down the center. That pad had once cinderblock onit then several small pieces of wood on top of that. The 2x8's rested on those pieces of wood. Just the look of it bothered me, so I was talking to them about how to support the beams if I wanted to replace those wood pieces. We then found out that via their digging that this other pad was only 6 inches thick. So I ended up having them extend what they were digging into the area under that pad so it could get a proper footing under it. They also redid the support on top of the pad.

End result was looks quite good and I'm happy to have the matter finally resolved.

Thanks again to GBR for his advice & time.
 
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Old 06-18-09, 03:52 PM
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Glad to hear the final resolve. Sounds a bit more than a DIY, job and I am glad they did it properly. Thank you for posting back as we don't often hear from someone after our advice is given. This just puts a smile on our faces when things go smoothly. Be safe, G
 
 

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