Grinding floor-how much removed?

[bluedog225]

I regret not having my shop floor finished dead flat. Instead of sloped to the doors. But done is done.

I have one man door that shuts fine. But when wide open, the clearance reduces due to the sloped floor. It catches the weather stripping and jams.

My question is how much floor is removed when prepping a floor with a floor grinder? 1/8”? Less?

Any insight appreciated. Thanks

 

[Fixr]

I regret not having my shop floor finished dead flat. Instead of sloped to the doors. But done is done.

I have one man door that shuts fine. But when wide open, the clearance reduces due to the sloped floor. It catches the weather stripping and jams.

My question is how much floor is removed when prepping a floor with a floor grinder? 1/8”? Less?

Any insight appreciated. Thanks

I suspect that question is like asking "how long is a piece of string?"

 

[bluedog225]

Maybe. More generally I was wondering if removing an eighth of an inch was fantasy or if that’s in the zone.

For example I know how much wood I can remove with the belt sander. I’ve got no feel for what a floor grinder removes. It might take off at 32nd and done in which case it’s not going to be that helpful.

 

[Bodj Built]

Maybe. More generally I was wondering if removing an eighth of an inch was fantasy or if that’s in the zone.

For example I know how much wood I can remove with the belt sander. I’ve got no feel for what a floor grinder removes. It might take off at 32nd and done in which case it’s not going to be that helpful.

I understand your question. A floor grinder can remove material plenty fast. A 4.5" grinder with the right wheel will work also, and quickly, but it's a mess.

 

[Firebrick43]

I regret not having my shop floor finished dead flat. Instead of sloped to the doors. But done is done.

I have one man door that shuts fine. But when wide open, the clearance reduces due to the sloped floor. It catches the weather stripping and jams.

My question is how much floor is removed when prepping a floor with a floor grinder? 1/8”? Less?

Any insight appreciated. Thanks

How about trimming the door and shimming or replacing the sill?

Or switch it to outswing so it doesn’t interfere at all with interior items and seals better against the weather?

Either much easier and better than grinding the floor

 

[Fixr]

How about trimming the door and shimming or replacing the sill?

Or switch it to outswing so it doesn’t interfere at all with interior items and seals better against the weather?

Either much easier and better than grinding the floor

There are also door sweeps designed to cope with unlevel floors. Might be the simplest solution. Example: https://www.tmhardware.com/About-Automatic-Door-Bottoms.html

 

[Firebrick43]

There are also door sweeps designed to cope with unlevel floors. Might be the simplest solution. Example: https://www.tmhardware.com/About-Automatic-Door-Bottoms.html

I don't know. I have not seen those and looking most are designed to be used on interior doors for sound proofing without any sill at all, which I can see them working very well in that application.

This one sort of could be used for weather sealing with a sill plate, but the sill itself would have to be replaced and or moved significantly which isn't possible on a lot of exterior doors


https://www.tmhardware.com/barzen-5...igh-soundproofing-surface-mounted-double-seal

Or you would have install one of the inset ones which you would need to cut the door any ways with a rabbet and many steel or fiberglass insulated exterior doors don't have enough structure in the bottom section to do this. And at that point just getting a new sill that is 1/2" higher and trimming the door 1/2" would be far cheaper and easier with the parts available typically at the big box store.

 

[Hank11]

I’d fix the threshold for a good seal. Mock it up with shims to see if it seems to make a trip hazard or not.

 

[bluedog225]

Thanks all. Some good ideas.

Unfortunately it’s a steel door set in a concrete wall. Limits some of my options. I could take the thing off and remove some from the bottom. That would be a bit of a project. I’ve shimmed up the sill so I’ve got a pretty good seal as it now sits. And the door clears the concrete. But it’s not a great seal.

One day I will finish this garage floor and if I’ve got the grinder here anyway I wanted to get a feel for whether some improvement to the area could be made without too much trouble.

 

[AEAdam]

I ground 2400sqft with a 20" floor buffer and a rented diamabrush diamond wheel. You need the right one. There are 2, a mastic remover with fewer diamond encrusted blades, and a concrete prep version with like 20 blades. You can easily remove 1/8", but won't be super fast. You can smooth and sorta level. You could try a hand grinder, but I doubt you'd be happy with the result. My local home center rents that blade for like $50/half day and if you rent in the afternoon, you can return it in the morning for 1/2 day. You should be able to fix that door opening in 1/2 day and it would be great.

FWIW, I rented that grinding thing for several days, at the end of which, I went out and bought one. I want to do my garage and my shop. They are like $700. Pretty sure I had a coupon for Zoro. I own the buffer. I was able to do all the initial grind on my floor (ground floor of my house to be) but hired a floor finisher to do the final polishing. For my shop, I think I will grind, then use coarse scotch brute pads to polish to whatever I can get, then densify and polish/burnish and be done. Won't be glossy, but straight from the grinder, the floor looks pretty great.

More:
We had a new floor poured and the contract said full polish and the contractor agreed. Day off, they said "no polish", hadn't priced that, couldn't do it. We fed them lunch. They used my tools, lasers for heights, wheel barrows, and they left me with this:

I had asked them about power trowels and they said "oh yes yes". But there were no power trowels used. I think they got tired and got off the floor too quickly. I was pretty upset about all of it. They were immigrants and not what I would call cheap.

A couple hours (like 2) with the grinder, I had this:

Had to see but the swirl and trowel marks were gone. You can see a little roughness around the drain pipes.


The concrete polisher guys were not super expensive. This is obviously the opening for where the stairs will be to the second floor. I lined the exterior walls with rigid foam to make a thermal break, since these are heated floors. For anyone interested, this wall is the bank side of the bank barn. We excavated it, parged it, waterproofed then, then spray foamed 2-3" and reburied it (along with a French Drain). So this exposed stone wall is acceptable for the interior. This photo was taken several years ago, there is no moisture ingress, and the floor has a few minor hairline cracks (that happened almost immediately) but no big ones anywhere.

I would not hesitate to rent a buffer and a grinding wheel and go to town on a garage. I started this thanks to inspiration from Garage Journal and I bought densifier from one of the vendors here. My garage floor is a broken uneven mess and I'm looking forward to the end of this project when I may rip it out and repour a new floor like this one. May even heat it like this one, because that was also easy.