Marshalltown Crain 822 6-1/2-Inch Segmented Diamond Saw Blade for 812H Super Saw

I used this blade to undercut a fireplace hearth for installation of a hardwood floor. It worked great in the SuperSaw (rented from Hiome Depot with only the standard blade, so we had to buy this special diamond blade, which Home Depot does not sell) which seems to be the only tool available to cut flush with the floor (with its recessed center screw). We cut through the concrete flush with the sub-floor and then another cut in the brick 3/4 inches above the sub-floor, both cuts about 3/4" deep, and then chiseled out between. It worked great, though it generated a lot of brick dust. Luckily we sealed off the room with plastic so we only had to vacuum up the dust in the one room. Then we put the hardwood boards right underneath which saved the trouble of framing the un-square hearth, and looks better because there are no gaps. Anyway, the blade worked great for cutting the brick, we were done with the job in less than an hour, in time to return the SuperSaw to Home Depot well within the 4-hour $18 rental period. Now we're done with the blade after less than an hour use- anyone want to buy a used blade? ;)

Had to cut out an opening for a built in Bbq through brick and concrete and worked very well.

Cut more then 100 feet of brick to install laminate flooring so I did not have to use quarter round next to the brick. Blade is still in great shape.

I had to undercut a stone fireplace to slide the laminate flooring under it. A previous reviewer had some great tips. Here are my suggestions. Mask off the room where the fireplace is. (Plastic sheeting on the door/hallway openings). Completely cover the floor and any furniture in the room (unless you like dusty furniture). Even with masking you get a bunch of unwanted dust in the house. Buy/wear a respirator! Lots of fine dust will be generated with this process.If you can, get a second person with a shop vac to go right before your cut ( look on "Youtube for "Undercut a Stone Fireplace", there's a UK video which shows the Crain saw with the diamond blade in action). As the other reviewer stated make two cuts into the grout/brick/stone. One on the deck (flush with the sub-floor), and second pass an eight on inch higher than your flooring material. How deep do you go? That depends on your fireplace. With a straight brick fireplace you can get away with a 1/2 inch deep cut, but with a stone fireplace where the stones are uneven it can very (I had to set the saw 7/8 inch to get the depth I needed). This saw blade is excellent for the job. Once you finish (and allow the dust to settle), take a chisel to make sure your grove is uniform). Shop vac up the mess. The blade was expensive, but worth it.

I used this blade to undercut a stone wall. The wall is about 18 feet long. So I cut a total of about 36 feet with the two cuts. It cut the the mortar like butter. The stone slowed it down but it still cut it pretty fast. I deducted one star from the blade because it was not straight. It had a slight wobble.