Are Fiberglass Porch Columns Hollow?
Yes!
In fact, all porch columns, no matter if they are round, square tapered or non-tapered fluted or plain are all hollow. Also when you look at the different materials: polymer stone, fiberglass, PVC and even wood they are all hollow. This has to do with the way each of them are made. The fiberglass and polymer stone porch columns all come from a mold that has the shape of the part. The fiberglass mixture is poured into a closed mold, rotated very quickly, and then then the columns dry while they are spinning leaving the column hollow. FRP porch columns are made in halves by spraying with fiberglass strands similar to the manufacturing of a fiberglass boat. The halves are glued together in the factory or on-site creating a whole column once assembled, glued and after Bondo is applied. A wood porch column is made by gluing staves together in a circular form and then turning and cutting them on a lathe. Lastly, PVC porch columns are made from a cut out of a flat sheet of PVC and then assembled in our factory (or on-site) to make the finished square product.
Of the four types of columns listed the PVC is the only column that is considered to be non-structural. The other three, when left whole, can hold up to 20,000 lbs each.
Each of the columns have an interior clearance that can be utilized when surrounding a structural support. It is important to know what this clearance is before ordering and it is also important to remember that a square post is bigger than a round post. The diagonal of the square is what the true width is and not the width of the post. If the interior clearance on a round column is 4” a 3-1/2” diameter post WILL fit inside. On the contrary, trying to fit a 3-1/2” x 3-1/2” square post inside a 4” diameter round porch column won’t fit as that diagonal is 4-7/8” width!
Hollow porch columns can also hide uplift systems needed for hurricane or high wind zones. These uplift systems are typically an all-thread rod that goes up through a header and is secured at the floor. The all-tread provides the uplift and the porch column supplies the down load needed to support the roof or porch.