Writing Specifications: Getting the Most Out of a Contract

Before you start writing a set of specifications (specs) you have to know what you want. You will also need to know in what order the events of your project should proceed. If you were writing specs for a new home, you would not want to start with the shingles, it is best to start with site work then move forward with the foundation etc. In the proceeding article, I told you that the best way to achieve this is to do your homework, this still applies. There are books and websites on almost every conceivable project you can imagine, make use of them. However, do not depend on one source, as most sources have a single regional point of view. Out west they do things completely different than they do it up north and down south they do things different than both. They also use different terminology in different areas, so once again, it is wise to hire a consultant, then double check him/her.

Let's start with a simple example, let's write a set of fictional set of specs for a deck on the back of brick home. First, we would want to decide how large our deck is to be, for our example, we will call it 12' x 24'. This is the title of our specs, then we will start with the foundation of the deck. Some decks are built right on cap blocks set flush in the ground, while others are set on concrete piers while others have the posts set in the piers. You must also consult your local building codes, because it may require a certain amount of piers or a certain way to fasten it to the home. For our purposes, we will set ours on poured in place piers. Then we will spec that all lumber will be pressure treated, however, it is not uncommon for them to be built of cedar or cypress, for cost reasons, we will stick to pressure treated pine. We will also spec that all fasteners are to be galvanized and that 16 penny nails be used in the framed structure but that all decking will be screwed in place.

Piers are to be poured into prefabbed cardboard sono-tube (sono-tube is a name brand form used to pour round piers or columns) set twelve inches into the ground with no more than six inches of sono-tube above grade. Sono-tube to be plumb and level and kicked to prevent movement while being poured. For our posts, we will specify 4x4 pressure treated posts at six foot on center, 4x4's to be notched to receive 2x8 framing. Interior joists to be 2x8's on two foot centers (sixteen inch centers is overkill on a deck, it also increases overall costs). Our exterior boxing band is to be doubled with the interior band being 2x8's and the exterior boxing band being 2x10's. With the rear boxing band against the house being a single 2x8 being bolted to the home with through bolts every twelve inches on center with the bolts being half inch galvanized with washers inside and out. Bolts to go through the brick and the interior boxing band of the home with the bolts being no closer than one and a half inches from the top or the bottom of the exterior band and alternating from top to bottom. Each joist is to be fastened using galvanized joist hangers with eight galvanized screws in each member.

For handrails, we want our 4x4 pressure treated posts to extend through the deck to thirty six inches above the decking for support of our rails. For our top rail, we want a 2x4 set on its side with a 2x4 cap. Our bottom rail will also be a 2x4 set on its side with 2x2's pickets set five inches on center (code often sets that these are no further than four inches between them so that a child cannot stick his head through them). For our steps, we want our risers not to exceed seven and five eighths of an inch and our treads not less than eleven and a quarter inch. To keep water from standing on our deck, we will specify that it slope at one quarter of an inch for every four feet. Decking to be five-quarter deck boards, running parallel to the home with no deck board to be shorter than six foot. Decking to overhang the sides one inch all around, with all cups in the boards to be turned down.

If I was writing that for a client, I would have written it out as a list with each direction being numbered. You might have noticed that I did not spec any reinforcement bars in the piers nor did I spec a concrete strength. If I was writing a spec for a driveway or a foundation, I probably would have specified at least 3000 psi strength concrete with 6x6 wire mesh in the drive or 3-#4 bars continuous in the foundation. This is up to you, placing rebar in a pier for a deck is overkill. In fact, a deck this small could easily be placed on cap block. Unless of course you are planning on putting a hot tub on the deck in which case I would have specified six by six posts with one every four feet under the tub and I would have beefed up the joists to two by twelves.

The variables are endless. What you have to decide is not only what you want, but what the end use is going to be. This same deck could easily be built with two by sixes if you wanted, but I wouldn't recommend it. You can also include drawings and sketches as part of your specifications to clarify what you want. Make sure that when you start getting bids for your project that you insist that the specs and sketches are to be part of the final contract. I hope this has helped you in some way, once again, if you don't know what your doing, do your homework. Then if your still uncomfortable with it, get some help, it is better to admit you don't know than to regret it later. You may come across some contractors who will not bid on your project because you know or it looks like you know what you are doing. This is a good thing, move on, legitimate contractors will appreciate the work you have done as it answers allot of questions that they should or would have had to asked you to start the process anyway. Good luck and good building.