Columns & Beams
Click below for help measuring.
A freestanding fiberglass pergola is not attached to a building and requires at least four structural
fiberglass columns to support
An attached fiberglass pergola is attached to an existing structure with a custom-made fiberglass ledger
board and is supported by at least two structural fiberglass columns.
Freestanding Pergola: Below is an example of a site plan for a freestanding pergola, the
squares in each corner represent the columns. In order to get accurate dimensions you will need to measure
your column centers. The 144” dimension below is an example of this. Using 10” cardboard cutouts on your
patio may be helpful. Please keep in mind that our standard overhang from the center of the column is 24” so
you will need to be mindful of any space constraints. For instance, a pergola with 10x10’ column centers
will have an overall size of 14x14’.
Attached Pergola: Below is an example of a site plan for an attached pergola. The small
squares represent columns and the line marked house is the house. Measurements are taken between the columns
on column centers, and from the house to the column centers. Our pergolas typically have a 24-inch rafter
and purlin overhang, this factors into the overall dimensions. The 12x12’ pergola for example has an overall
size of 14x16’. In other words, the rafters are 14’ long as they only overhang on one end and the purlins
are 16’ long as they overhang from both sidea. When measuring, dimensions are taken from column centers.
Typically, our pergolas are between 8’ and 10’ tall to the bottom of the beam. Please specify how tall you
would like your pergola and remember to measure the height of any windows and doors that might obstruct the
ledger which requires a space at least 8” tall.
True 2x8" fiberglass beams:
Our true 2x8” fiberglass double beam is our standard offering. It allows for column to column free-spans
of up to 19 feet and can legally be used as conduits to run wires in most states.
True 4x12" fiberglass beams:
Our massive 4x12” beams are perfectly proportioned and make a statement. If you are looking for a
structure with more of a sense of “presence” these beams are for you. With the ability reach 22 foot free
spans these beams allow for more unobstructed space. They are available as an upgrade option on most
A critical aspect during
the pergola design stage is ensuring an adequate mounting surface to accommodate the structural fiberglass
columns. Our columns cannot rest on grass, gravel, soil or paving stones. Concrete footings or a concrete
slab is required to properly install any pergola and is vital to preventing uplift and structural
stability. Both our freestanding and attached pergolas can also be deck mounted provided the is
structurally sound enough to support a pergola. If footings or a slab are used an 8” long 5/8”
stainless-steel threaded rod is epoxied into the footing or slab and later coupled with another
stainless-steel threaded rod that runs to the top of each column where it is fastened and provides
protection against uplift.
Concrete Footings: When concrete footings are used we suggest a sonotube footing no
smaller than 14” in diameter. The pier must be at least 36” deep or to frostline. Local regulations vary
by city and state and may require a deeper footing. The 5/8 in stainless steel threaded rod can be
either wet-set in the concrete or expoxied in place later.
Concrete Slab: When a concrete slab is used we suggest thickness of at least 3.5” and
a shallow footing below the slab in each column location. Local regulations vary by city and state and
may require a thicker slab. The 5/8 in stainless steel threaded rod can be either wet-set in the
concrete or expoxied in place later.
Masonry Piers: A footing is required under a concrete filled masonry pier or wall.
Wet-setting the threaded rod in the sonotube footing is preferred. Some information we need is:
Masonry Piers: While a footing is still required in this alternate configuration, the
threaded rod can be wetset in the concrete inside of the pier or epoxied in place later. We request that
the pier is pinned to the sonotube footing with #5 rebar.
Deck Mounting: When mounting a pergola to a deck, structural aluminum deck mounting plates
are required and are furnished by Baldwin Pergolas. A 5/8” stainless steel threaded rod is run from the deck
mounting plates to the top of each column where it is fastened and provides protection against uplift. The
deck must be structurally sound and showing no signs of rot. We do not recommend mounting to composite
decking as it can easily detach.