More do-it-yourself types are building storage sheds, play houses, hobby studios and potting sheds to enhance their property and serve useful purposes. Lots go into home construction projects of these types but nothing is more important than getting the building foundation right.
A poorly constructed, out of square foundation can cause a host of other irritating problems as a construction project progresses. Laying out a perfectly squared foundation can be reasonably simple with the right tools and the application of a little construction know-how.
Tools and Materials for Laying Out Building Foundations
A few simple tools and materials are needed for laying out a foundation:
- Circular saw
- Electric drill
- Framing hammer
- Sledgehammer
- Measuring tape
- Line level
- Plumb bob
- Mason’s line
- 2 in. x 4 in. lumber
- 2-1/2 in. wood screws
- Wooden stakes
- Masking tape
- 8d Nails
Construction of Foundation Batter Boards
Batter boards are horizontal lengths of lumber with two parallel, perpendicular legs attached that are positioned just outside the corners of a proposed building foundation. Used in pairs at each of the four corners of a rectangular foundation site in conjunction with Mason’s line, batter boards simply the process locating the foundation corners and getting the foundation squared.
The first step is to assemble eight batter boards. Cut twenty-four, 24 inch long lengths of 2 in. x 4 in. lumber. Leave eight of the lengths with squared cut ends and make a point at one end of the remaining sixteen that will serve as batter board legs. The points will facilitate driving them into the ground later.
Attach two parallel legs to each of the eight horizontal lengths of lumber using 2-1/2 in. wood screws.
Setting the Foundation Batter Boards
Perform preliminary measurements to establish the temporary four corners of the foundation and mark them with wooden stakes. Set two batter boards in an L-type configuration at each of the four corners. Batter boards should be set about 18 to 24 inches behind the corner stakes. Batter boards should be driven into the ground until secure and the horizontal pieces should be roughly level.
Sighting the Building Foundation Corners
Drive a nail into the horizontal length of lumber parallel of one batter board and attach Mason’s line to it. Stretch the line to a non-diagonal opposing corner and attach it to the horizontal length of lumber of that batter board, aligning the nails and line with the corner stakes. Attach a line level to the Mason’s line and then pull it taught. Check the line level to make certain the Mason’s line is level before tying it off on the second nail.
Run additional lines between the remaining batter boards, pulling them taught and attaching them with nails until a complete perimeter of level Mason’s line has been formed to outline the foundation. The lines will intersect each other at each of the four corners, forming 90 degree angles.
Check the 90 angles formed by the perpendicular line intersections using the 3-4-5 method. Measure 3 feet along one line forming a 90 degree angle and mark it with masking tape. Measure 4 feet along the other line forming the same 90 degree angle and mark it with masking tape. Now measure the diagonal; between the 3 foot and 4 foot marks and the result should be 5 feet if the two lines are perfectly perpendicular. If they are not make adjustments until the result of the 3-4-5 method equals 5. Repeat at all four corners and once the result of the diagonal measurements at each corner equal 5, all lines are perfectly perpendicular and the perimeter formed by the lines is square.
Attach a plumb bob at each of the four intersections formed by the Mason’s line and plumb down to set the corner stakes at the exact foundation corners. Once the stakes have been driven, a perfectly squared foundation has been laid out and foundation construction can proceed.
Foundation Construction Methods
This method of laying out a squared foundation works with a variety of foundation construction methods. Preparation for the installation of stem wall foundations, pier foundations and on grade slab foundations will all be completed using the method. Once the foundation concrete forms or pier holes and forms are in place, the batter boards can be removed.
Reference:
- Thallon, Rob. Graphic Guide to Frame Construction. Newtown: Taunton Press, 2009. Print.
Larry Darter - Larry Darter is a freelance writer and published author with three books to his credit. He is a graduate of the Univ. of Central ...
