Pouring Cement Floor

[lzicc]

I have a question on setting up forms to pour a cement floor. My walls are up and I am under roof, so I can't put forms around the perimeter since the wall is there. How would I put forms in so I that I have a guide to run my screed board on?

What I would did in the past is stake a 2x4 on edge lengthwise about a foot from the wall, one on each side and use that as my guide for my screed board so I could roughly level out the poured cement, then I would pull the 2 forms outs and fill in the void where the 2x4's were with cement before it would start setting up and float it over then finish it. Is there an easier way to do this this that I am not thinking about? I don't think I could do a good, level job without using the forms as a guide.

 

[64dragnwagon]

What type of construction are the walls? I can't picture it. What are the walls setting on? Need more info to help.

 

[Zeke]

Set your 2 x 4 screed boards on stakes with the bottom of the board on finish grade. Put guides on your screed on the top so that the screed "floats" on the boards. Leave room to move back and forth.

Not much to fill when you pull the stakes. You can do this as soon as you're out on the slab on your knee boards.

 

[ConCretin]

You could use the 'wet screeding' method that most pros use.

Level the concrete with a magnesium trowel to create pads 10 or 12' apart. Use a level, laser or measurement to establish the elevation of the pads.

Use a screed to level the concrete between the pads to create concrete screed rails.

Turn 90 degrees and use your two screed rails to level the concrete between them. It's much easier with two people on the straightedge and one or two raking. Rent a Vibrascreed to make the job a lot easier.

Set over and repeat.

It takes a little practice but it doesn't require solid rails or forms.

Another option is a product like Accu-screed. It consists of plastic saddles that support removable pipes that you can screed off of.

Hope that helps

 

[carusso1]

To combine what Zeke and LLWillysfan have suggested, if your walls are CMU's (cement blocks) or something that you don't mind drilling into, anchor a 2x4 to the wall using a few tapcons. Set the bottom edge of the 2x4 2" above the elevation of your proposed finished floor. Then set another 2x4 about 8' or 10' away like you normally would for forming concrete just as you described above. Use a 2x6 to screed with a 2x4 sized notch cut out of one end so it can ride on the 2x4 you anchored to the wall as a guide/track. Pull the 2x4 that you set 8' - 10' away and use the portion of the slab you just poured as your form for the next pour.

I have also seen people use expansion joint material along the walls as forms. Tack it to the wall using some cut nails so it will stay in place. When your all done and the concrete has set, trim the expansion down with a utility knife and caulk the joint.

Just some ideas. Hope they help.

CAR

 

[Gary S]

Another option is a product like Accu-screed. It consists of plastic saddles that support removable pipes that you can screed off of.

That is how we do it. Drive short pieces of rebar to the correct depth to hold the plastic saddles. Then lay pipes on the plastic saddles, add concrete and get it level. Remove the pipes and saddles as you go.

 

[sr4440]

Although not how I did it, if I had to do it over again I would have used a rotating laser level and marks on the screening board


Joe

 

[robmints]

How big is the floor? You might want some tools. Grade laser, power screed, power trowel with floats and trowels ( better than the combos).

Set witness marks with a grade laser and chalk line the perimeter. Use the wet concrete to make approx 1 foot square piers about 7 1/2 feet from the wall about 4 feet apart ( or what you are comfortable with) and power screed between the line and piers. The piers height is set with the grade laser. When you are done the first row, start all over in a new row but use your finish height you just made instead of the wall. You will need a foreman who has done it before and lots of help for the placing. You will need help for the hand floating and troweling of the perimeter. Don't forget to cut your controls that day, there will be a lot of stress in that big flat piece as it heats and cures.

My best advise, if you need to ask, get some experienced, knowledgeable help.

 

[DMT]

How big is the floor? You might want some tools. Grade laser, power screed, power trowel with floats and trowels ( better than the combos).

Set witness marks with a grade laser and chalk line the perimeter. Use the wet concrete to make approx 1 foot square piers about 7 1/2 feet from the wall about 4 feet apart ( or what you are comfortable with) and power screed between the line and piers. The piers height is set with the grade laser. When you are done the first row, start all over in a new row but use your finish height you just made instead of the wall. You will need a foreman who has done it before and lots of help for the placing. You will need help for the hand floating and troweling of the perimeter. Don't forget to cut your controls that day, there will be a lot of stress in that big flat piece as it heats and cures.

My best advise, if you need to ask, get some experienced, knowledgeable help.

That's pretty close to how we did it back in the day except we put stakes every 7.5 feet set to height pre-pour. During the concrete pour we would level to the top of stack then just knock them down with a sledge.

 

[Daniel Dudley]

That's pretty close to how we did it back in the day except we put stakes every 7.5 feet set to height pre-pour. During the concrete pour we would level to the top of stack then just knock them down with a sledge.

Done this a lot. I knew an excavator who did sidewalks, and he would use a permanent metal expansion joint for screeding. He never took them out. Doubt you could power trowel over them, but I have never used them, so I do not know.

 

[lzicc]

Those are some good ideas. My walls are CMU. After reading all of this, what carusso1 said may be an idea that would work for me, although I thought about renting a power screed to help offload allot of the work. I guess a power screed would work with that idea. I never used one before, but I have limited help. My floor is 25' x 40'. I was going to do it in 4 separate pours of 12.5' x 20' since I have limited help.

When I would manually screed, we would have a person on each side of the screed sawing back and forth. Of what I have read, I guess a power screed doesn't really saw back and but just vibrates. Am I correct in saying that?

 

[robmints]

When I would manually screed, we would have a person on each side of the screed sawing back and forth. Of what I have read, I guess a power screed doesn't really saw back and but just vibrates. Am I correct in saying that?

It wobbles back and forth and forward and back. The engine drives an output shaft that is about 1 inch eccentric, the eccentric goes in a socket bolted to an aluminum screed board. When you use it you just pull slowly backwards and your helpers come-a-long as needed.

 

[NUTTSGT]

Although not how I did it, if I had to do it over again I would have used a rotating laser level and marks on the screening board


Joe

We used a laser level on my floor when it was poured.

Mounted on the post above the wheelbarrows, you can see the laser. Leaning against the wall (breaker box)is the 2x4 with the laser detector mounted on it.