Slippery Rock Gazette

Bob Murrell 

Special Contributor

Photos provided by Bob Murrell

Warning! This article contains some simple math. Beware!

Above: An example where the existing conditions can create some complexity in the job: here, marble flooring butts directly up to wood paneling.

Above: Investment in equipment like this planetary machine will improve your lippage removal capability, and allow you to bid more complex and specialized jobs.

Above: Don’t forget to include consumable supplies like masking materials to contain your dust and slurry. Poly drapes and tape are a reoccurring expense with almost every job, even though it may only be 5 to 10 cents per square foot.

I have been been asked thousands of times in my career what should contractors charge and how much does it cost to operate? These questions and more are dependent on many variables, of course.

What are the labor rates in your area? What is the surface being worked on? How big is it? How many steps are you doing? How cut up is it? Does it have lippage? What does the customer want? Is the customer a preferred repeat customer? There are many questions that need to be answered in order to know costs and submit bids.  

I will in no way presume to tell you what to charge or what all of your operating expenses might be. I can tell you what customers from all over the country tell me and what the basic costs of products that I am involved with are. I will most always give you my opinion, even though we all know what opinions are like. In any event, feel free to make my opinion yours. No charge.  

Product costs are one of the smaller parts of operations as compared with labor, overhead (building and equipment) and insurance. They are, after all, consumables that normally get passed along to the customer. Labor, overhead, insurance, vehicles, and utilities are normally somewhat fixed costs, but can be harder to quantify. 

When we are talking about diamonds, pads, chemicals, and prep materials, these costs can be converted to a per square foot cost when the approximate coverage is known. The same is true of fixed costs if you can average your yearly estimated total square footage completed.

I have generally found that resin bond diamonds will cost about 5 to 10 cents per square foot, based on the material being honed, of course. As we know from previous articles, softer materials such as limestone are more abrasive than marble and diamond wear is much higher on these stones. 

So, figuring 10 cents a square foot is a fairly good place to start with resins. Of course, 50 grit resins do more work than 800 grit resins and will generally wear at a faster rate. But if you figure the general average to be 10 cents per square foot per step you should be OK on resin costs. A five step resin process will therefore cost about 50 cents per square foot.   

Metal bond diamonds cost more but generally last much longer than resin bond diamonds. The average cost on metal bond diamonds is also about 10 cents per square foot per step. So if you were to do two steps of metal bond diamonds and five steps of resin bond diamonds, your approximate costs would be 70 cents per square foot.

Use of polishing products like 5X or Stone Polishing Compound calculates to around 5 cents per square foot based on the larger sized container price. Intensive cleaners calculate to around less than 5 cents per square foot. 

Impregnators and sealers can cost upwards of 15 to 20 cents per square foot for the product. Porosity and density determine coverage rates while quality and type of product determines the per bottle cost.  

Other consumables such as poly draping and masking materials which are normally applied to protect vertical surfaces when working floors or countertops, costs about 11 cents per lineal foot. Of course there are also rags, buffing pads, razor blades, blue tape, and brushes for both hand work and floor machine work. So another 5 to 10 cents per square foot should be added to the costing to cover all of these consumables. 

So now we know some of the basic product costs. What about gas for vehicles, repairs, the time and scheduling for submitting test areas, and expenses when doing projects out of town? There are many other costs of doing business that must be calculated and added into the bidding procedure.

As we all know, managing company employees can demand most of the business owner’s time and certainly have the potential for providing many problematic issues. Labor rates vary from one part of the country to another. I have seen some owners that pay around $15 per hour and others who pay over $25 per hour for experienced technicians. Health insurance and other benefits can also be part of compensation packages.

So lets put some simple calculations together. Say you pay two technicians $25 each per hour (1 standard floor machine operator and assistant) and they can do approximately 500 square feet of light lippage removal to polish (lets use a six step process starting at 70g metal and going 50g through 800g resin) in a 10 hour day on an easy to work light colored marble. That is a $1.00 per square foot cost for labor. Add that to the 60 cents per square foot for diamonds, 5 cents per square foot for polishing, and another 5 cents per square foot for accessories and you have $1.70 in product and labor costs so far. Note that this figure does not include vehicle and equipment wear and tear expenses, gas, lodging, your overhead…you get the idea.

For many years I have often told customers for the above type scenario that they should be charging between 50 cents to $1.00 per square foot, per step. The lower end is for larger projects with easy-to-work stone that is open (not cut up) and has good access to water and electrical supply. The higher end would be for the opposite of this. Of course really difficult projects like black marble with white borders in ornately cut up installations (narrow hallways, small bathrooms, etc.) could necessarily demand an even higher price. A 35% to 50% profit margin should be the goal, in my opinion.

I have often said that it is typically easier and more cost effective to do a 100,000 square foot project than a smaller cut up 1,000 square foot project. Reducing costs is all about increasing production not necessarily lowering product costs. More and larger machines is one way to help accomplish this task.  

I know that I have merely touched on subjects that comprise some of the costs of doing business. Each company will need to do their own cost analysis. As always I suggest that you consult with a reputable distributor and solicit their input for product costs and coverages. Of course ultimately, the operating costs and bid prices are your decision as the owner of the company.