Concrete formwork

[MiamiCuse]

I am redoing the landing area coming out of the front door to the driveway. Right now there is a step that is almost 9" tall and I wish to make it about

6" or so and slope from there to the beginning of the driveway that is about 6' away.

If it is an open area I can always cut some 1x and use it to create the form work for the concrete. However, in this case, the area is between two existing walls. If I cut two pieces of wood and fix it to the ends and do the concrete, when it's done I cannot remove the wood anymore. Any idea how I can control the slope of concrete when the edges are two walls?

Thanks in advance,

MC

[dpb]

One thing I've done in similar situation is to form up each end a brick (plus joint) width or length away from wall and then pour. After set, backfill edges and lay brick or pavers along edges.

Another way is to simply pour the center section then use it and freehand the narrow outer section w/ a formed edged between the sections.

OTOH, if you use foam board or similar behind form against wall there's enough give to get a form out if you leave a portion to get ahold of for starters and don't fit it too tightly at ends so it's got some wriggle room.

Then again, I've seen the forms left in place and when the finally disintegrate, fill it in. Not my preferred choice, but in TN one saw lots of stuff... :)

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[Rick Samuel]

Can't the existing walls work as part of the forms?

[aemeijers]

Traditional way is to use that black expansion joint stuff against the walls, cut to shape before placement. Stuff we used in stone age looked and smelled like celotex sheathing, but with a higher tar content. Not sure what the modern equivalent is. Of course, when it fails, you have a place for leaks and ice to form, if that is a concern. Are the existing walls on each side wood or brick? If brick, to keep the brickwork pretty, cover the bottom couple feet with visqueen duct-taped in place. After concrete cures, just trim off with a utility knife. If wood, butting them up to concrete is not recommended, even with flashing in between. Might want to consider forming up a sloped drain slot so the wood stays dry.

A 3" fall in six feet is almost a ramp. You are going to want a stiff concrete mix, and a pretty aggressive broom finish to guard against slipping. Somebody will jump in here with what code says about that- I haven't a clue.

Unless you have your heart set on DIY, I would have a couple local flatwork guys estimate the job for you. An experienced finisher can float that slope by eyeball better than you or I could with a screed board running on rails, using nothing more than a string line on the walls. If you do the demo work, any form building, put down the gravel and the reinforcing fabric, and do the cleanup, it might not even be very expensive. He could knock it out in a couple of hours.

-- aem sends...

[Joe]