Expert: Bruce E. Johnson - 5/15/2011

Question
I am building a larger patio pad. I have removed the old one and removed sod, dug a 12" x 6" deep footing with 2 #5 rebar around the edges of the pad. I formed the entire space with 1 inch x 12" wide plywood along three sides, using the house as the missing side, and the forms are above the ground by only 4". The pad thickness will be 4" and will be poured at the same time. The pad length is 34 ft x 14 ft wide. The pad is sloped to allow 3.5" of slope away from the foundation of the home. Also the pad is sloped on the length as the property is sloped for drainage approx. 6". My Question, I planed to inset forms to split the pad width to 7 ft deep and the length divided up into 5 even spaces of 6.9 ft. this was done to be able to screed the sections , then pull the forms out in order to float the surface. Once done with the floating I would edge and score the pad. Can the screed process be done on the entire space without the extra forms?  
Any other way?

Dave

Answer
Hi David, I generally set up grade screeds to work off.  It is a 2x4 on edge and staked in place so that the bottom of the 2x4 is set at the top of the slab.  Then use a drop screed across that when pouring.  But there are varying methods as well.  You can buy or rent saddles that attach to round steel stakes that support a 2x4 or steel screed.  You can pull string lines and mark elevations on wood stakes and screed to them with a long straight edge..forming is another way, as you mentioned..this method works good because it allows you to get nice control joints that will help eliminate cracking..when pouring this way I hopscotch the pour to allow a section to set up a bit while pouring a different unrelated section..saw cuts 1" deep or 1" joint tool should be done every 100 sq feet minimum..sincerely Bruce Johnson