# Ideas/Suggestions for filling large gaps in antique flooring



## tazmaan (Sep 21, 2012)

Hi All,
I have a large project, about 4000 sq ft of antique wide plank fir flooring (2×10-2×12) in an existing house. Problem is, there are large gaps between the boards from 1/4" all the way up to almost 1/2". Whether they were caused from the floor being initially put in green, I have no idea. Whatever they used to fill these gaps at some point has cracked out and needs to be refilled. 
Herein lies my dilemna. I am looking for suggestions on what to use to fill these large gaps. 
The options I know of are:
1. removing the flooring and respacing them so they are tighter - not an option for me
2. cutting strips of wood to put in the gaps - not overly excited about this option, as it would be ALOT of different sizes of strips, and alot of labor to cut them all down and install
3. using rope stained as desired to stuff in the gaps - not sure about this one, seems like the finished look would be pretty unusual.
4. Mixing sawdust with sanding sealer and pouring it into the gaps - i have experimented with this a bit, but not sure if it's the best method or not
5. I have also experimented a bit with using Urea glue, but am not sure this would be ideal either. Without letting it sit thru a season to see how well it may hold up to whatever movement I'll still get out of these boards.

Anyone have any other suggestions, or have tackled this type of problem before?

I appreciate you reading and your feedback!

Thanks
Jim


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## patron (Apr 2, 2009)

had the same problem
they had used 2×12 construction hem/fir
with 1×2 redwood strips in between them

everything dried out and moved
gaps from zero to 3/4" 
waving back and forth

my solution was to rip beveled strips of redwood
(2x stock)
at about 3 deg or so
and keep flipping the board over and over
(end for end)
and just eyeballing the widths

in the floor itself
i just laid the beveled strips in the gaps
and cut them to whatever length needed
so they were still proud (at least 1/4" off floor)
and finding another wider or narrower to continue
the lengths didn't mater
as they just butted to each other
to fill the seams as they wandered in width

took them all out next to their spot
and ran glue to both sides of the open gap
then put them all in
and with a backer board and a hand sledge
beat them home

they tapered up and down exposed on the floor

after the glue dried
i used an adze to trim them close to flush
and found that chopping down first about a 1/2" to 3/4" 
kept the grain from running down under the floor height
and leaving an uneven top
(a sharp chisel would work too)
then a belt sander brought everything flush

after all was said and done
you really had to look for any 'waves' in the widths

in your case with all fir
it should be a snap to get it nice

hope this helps


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## MNgary (Oct 13, 2011)

Maybe filling with black epoxy like is often done when working with mesquite ??? I doubt you will find a filler that blends in, so perhaps the contrasting color.


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## BillWhite (Jul 23, 2007)

Dang Patron!!! How long did that take?
Certainly was/is the craftsman way, but I hope ya got well rewarded.
You have my applause.
Bill


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## tazmaan (Sep 21, 2012)

thanks for the replies thus far. 
Patron, yes, that sounds like ALOT of work, and I am not sure that that is the route i'd like to go. Remember, I am talking about 4000 sq ft plus of this problem, so that'd be a nitemare. But it isn't completely off the list, just toward the bottom 
MNGary, can you point me to the product you are referring to? How does epoxy handle movement? 
Ideally, something I can mix and pour into the crack, that hardens but still allows for some movement so it doesn't crack out so fast. And of course, that wont run me a fortune, since I have SO much I need to fill.
As far as blending in, I am not too worried about that. I can just error on the dark side, as it's antique floor and different color gaps are fine by me.


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## OnlyJustME (Nov 22, 2011)

there is also option 6. lay a new floor on top of it. lol

How about what they use on log cabins? i think it's called chinking? don't know if it can be used on the floors though.


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## tazmaan (Sep 21, 2012)

yeah, no new floor on top 

The chinking was actually my first thought when I first saw this problem. I am not sure if it can work on floors either, since it's very flexible (I vacationed in a fancy log cabin in MT a couple years ago, and it had it between the wall logs, when you push on it with your finger it gives very easily). I can see my kids picking at it, or someone's heel getting stuck in it etc. Not sure if its an option or not.


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## Promod1385 (Sep 21, 2012)

I would reach out to a local hardwood flooring re-finisher and see what they have available for products to fill these gaps. I have fur floors in my house (100y/o brick farm house in St Paul MN) and recently had them refinished. I dont know the products he used but whatever type of finish he used filled some pretty large gaps in my floors.

Best of luck! Let us know how you do it.


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## tazmaan (Sep 21, 2012)

Thanks. I can't seem to locate any good recommendations from local refinishers here. It doesn't seem like too many of them have had to refinish or work with these old floors.
Any chance you could ask your guy what he used? Did you have gaps as large as mine filled?


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## patron (Apr 2, 2009)

filling with epoxy
needs it's own attention too
as it cures air bubbles come up
they need to be burst 
with a spray lacquer thinner bottle
or a hair dryer
or when you sand they will be little craters
that still need filling
and walking around on the floor for this might be a mess

the strip method i did
didn't take that long
once i got into the rhythm of it
i have used the same system 
on plank counter tops
that have varying gaps too


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## Dennisgrosen (Nov 14, 2009)

if you can´t see thrue the gab and only can see the groove 
then its possible to make it look like a ship deck 
by messuring the wides gab and then run a straightbit on a router 
in them so they get the same groove 
then you have two options ….
1. you use blue tape along the grooves before filling with a kind rubber joint filler 
an excample http://www.danalim.dk/produktkatalog/byggeri/marine/merbenit-DC25/
when you have overfilled the joint a little you scrabe of before removing the blue tape 
the filler usualy dry 3mm (1/8) per day

2. don´t use blue tape and just over fill the groove 
when the floor is dry´d compleetly you take an overdimentionfloor sander 
and sand diagonal on the floor boards two times the second time turned 
90 degree from the first then you finish sanding with the grain

now you can oil/wax/ the floor but be aware that many fillers don´t like lack 
if you ask Shipright I know he can explain the step to you

the benefit you get from using a jointfiller is that it will take the expaniton and contraction very well

here is an exsample from a house and from a terasse not the best excamples sorry
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.
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.
.
good luck with the floor what ever you deside 

Dennis


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## Dennisgrosen (Nov 14, 2009)

forgot to say you can get different collours on the filler

Dennis


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## tazmaan (Sep 21, 2012)

I don't suppose you know of this product or similar sold in the US?
Looks like it could be a good option, depending on the cost


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## patron (Apr 2, 2009)




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## Loren (May 30, 2008)

I just fixed a small one by hand but for a bunch, I would use a router
and straight edge to cut the gaps to 1 or 2 uniform sizes with tapered
sides. Then make tapered strips and you should be able to make
the installation an almost painless process.


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## bandit571 (Jan 20, 2011)

Simple, really. One word need apply, OAKUM. looks like just old hemp rope. They even made a special "chisel" to stuff the oakum into the joints. Same "old rope" that plumbers would put into cast iron pipe joints, right before they poured the molten Lead to seal the pipe joint. kept the lead away from drinking water that way. Look up Oakum for floors. Seasons change, and the oakum will go along for the ride. No glue, no fasteners to catch a bare footed toe on.


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## crank49 (Apr 7, 2010)

If you were talking small thin cracks or holes like nail holes, I'd suggest a filler made from shellac and sawdust. works great, not expensive.

For anything over an 1/8 inch I'd go with Patron's method. Filling big gaps with a liquid and expecting it to stay is wishfull thinking and something you either would not be proud of or would have to re-do. Any filler will have shrinkage or off-gasing when it dries/hardens.

If you try any method of cutting or routing the grooves to uniform width, be prepared to cut a bunch of nails.


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## tazmaan (Sep 21, 2012)

luckily it's all face nailed, so no worries on hitting nails with router. 
Now the gaps to fill are 2" deep, would I need to fill the entire gap with strips if I were going to go that route? Or just fill the top 1/2", 1" etc?
could you clarify this portion of your post
--
after the glue dried
i used an adze to trim them close to flush
and found that chopping down first about a 1/2" to 3/4" 
kept the grain from running down under the floor height
and leaving an uneven top
(a sharp chisel would work too)
then a belt sander brought everything flush
--
I am not sure what an adze is, and am confused as to your reference to 1/2 or 3/4, as you said they would only be proud 1/4"?

Thanks

Bandit:
Any ideas on where to order the oakum rope online? I'd need hundreds of feet of it, so am not sure if it'd be cost effective or not. I am not sure if manila or sisal rope would work the same, and take stain well enough?


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## tazmaan (Sep 21, 2012)

you use that to trim strips flush? that seems odd?
I guess just belt sanding them down would be the way to go, or using a hand plane or something


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## patron (Apr 2, 2009)




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## bandit571 (Jan 20, 2011)

Go to LOGHOMESTORE.com Or look up Oakum and see all the suppliers. Log Home Store sells by the pound, with 50 pounds being about 100'. Used to ************************* gaps in floors , and log cabin walls.


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## gfadvm (Jan 13, 2011)

David, I love your high tech sketches! You are my kind of guy and your suggestions are always practical.


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## MNgary (Oct 13, 2011)

Tazman, I haven't personally used epoxy, but have seen demonstrations where the two parts are mixed together along with black colorant and then poured into knotholes and other gaps such as wormholes.

If I recall correctly Norm used it when building bookshelves of mesquite. Perhaps visiting the Yankee Worksop web site will help.


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## roman (Sep 28, 2007)

Patron is on it

everything else looks way worse


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## gfadvm (Jan 13, 2011)

Yep, Patron has the best answer (as usual).


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## tazmaan (Sep 21, 2012)

how much would i expect the boards to continue to move seasonally? Wouldn't putting strips in there result in the same problem, with the strips then popping with floor movement?
I may be leaning toward the rope route, however oakum is way too expensive (especially since i'd need like 2000 feet of it. I may be limited to using manila or sisal. Planning to do a test area with some sisal I picked up and staining it.


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