How Much Do You Really Need?

     You can determine how much wallcovering you need by one of two methods.  The most common method is the 'square foot method'.

Square Foot Method:

     If you were to measure the distance around a room and multiply that number by the height of the room, it would give you the number of square feet in the wall space of that room.  My bathroom, for example, has two walls that are eight feet wide and two walls that re five feet wide.  The ceiling is eight feet height.  (5+5+8+8=26, 26X8=208 sq. ft.)

     Now that you know how many square feet of wall space that you have to cover, you can divide that number by the number of square feet in a single roll of your wallcovering. The sample book from your wallcovering store will tell you how many square feet are in a roll of your chosen wallcovering.  If you have a stock wallcovering, it will be on the label or wrapper on the roll.

     Using the square foot method on my bath, I would divide my 208 square feet by 36 square feet for American rolls (which have been very hard to find since 1990) or 28 square feet for European rolls.  American: 208 / 36 = 6 rolls, European: 208 divided by 28 equals 8 rolls.  These are very common sizes for guest and hall baths. 

     When I first wrote these figures, over 15 years ago, there were still a lot of "American" rolls being sold.  Today they are almost non-existent.  Most wallcoverings are 21" or 27" wide at the turn of the century and 36" wide grass cloth is coming back in style.  In fact, you should consider 25 square feet as the most reliable number to divide into your total square footage. 

     It is a common practice to reduce the amount of wallcovering you order by one half roll per opening (door or window).  You should only do that with a random match wallcovering.  You want to have extra footage to cover trimming, waste from repeats (the larger the repeat, the more waste you are likely to have), flaws in the wallcovering (occasionally there are some), and mistakes you might make. 

     If you run out, you may have a hard time getting the same lot number again (not to mention the frustration of not being able to finish a job when you need to).  Most stores will take back double rolls for a small re-stocking charge.  It's worth the extra cost to have too much. 

Strip Count Method:

     The most accurate way to determine just how much wallcovering you need is to count strips.  Professionals use this method because some materials are extremely expensive and the customer may not want to have much wallcovering left.  To count strips you need to know how the wallpaper is packaged, in double or triple rolls.  Once you know the length and width of the product, you can determine how many strips can be cut from the packaged rolls. 

     If we use grass cloth as an example, it is usually packaged in double rolls that are 36" wide and 24' long.  For most homes you would get three 8' strips to hang.  But look how this changes if you have 9' high walls.  Now you can only get TWO long strips per double roll even though you have 6' left over. 

     The advantage to strip counting here is accuracy.  If you figured square footage, you would have come up with a number that would not take into consideration the number of long strips you would need.  You might have enough footage, but not enough long strips to do the job correctly. 

     Strip counting will also help you with large repeats.  You can divide the length of your roll by the length of your repeat and see how many repeats you can get from each packaged roll.  Once you know how many repeats it will take to make one strip for your wall height, you can determine just exactly how many strips you will get from your rolls.

     For example, a 45" pattern that is packaged in triple rolls that are 27" wide (a common size) will render you 12 repeats.  45' =  540" divided by 45" = 12 repeats.  If you have standard 8' high walls (96"),  you will need three repeats (135") for each strip because two repeats (90") will not be long enough.  You will only get four strips that are long enough out of a triple roll. 

     If you figured square footage, you would have come up short.  Even if you had divided the roll length by nine feet (a foot longer than your walls), you would still be short.  Who said you would never use your high school math again?