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Discussion Starter #1
I realize there are a number of Pergola posts; however, I couldn’t find the info I needed. Hope another one if ok? :)

I plan to build a 16 x 16 ft. Pergola over a paver patio 18 x 18 feet. I would appreciate any comments on the design and materials. I have not decided between Cedar and PT. My preference is Cedar; however, the available dimensions and cost make it a challenge.

Location considerations: Cold winters and winds can easily gust at 65 mph!!

Posts (6) 6 x 6 on concrete footers app. 40” deep
– (4) corner posts
– (2) center posts of north and south sides to support “center” beams

Beams 2 x 12 x 20’ pressure treated (PT);
– (3) parallel sets of 2 beams sandwiched on posts app. 8 ft. apart
– (2) beams per each of 4 sides, sandwich posts, bolted
– (2) beams between center posts (16 ft span, including beams), sandwich center posts, bolted
-- Cedar max available dimension is 2 x 8 x 16.
- With (8) posts, would it be feasible to use 2 x 8 Cedar sandwiched on perimeter posts,
max span of 8 ft.?
- Center span is 16 ft – only option would be 2 x 12 PT?

Rafters 2 x 6 or 2 x 8s x 19’
-- 16’ plus 18” overhang each end
-- Span between beams app. 8’
-- Cedar max length 16 feet, therefore, it would require (2) 2 x 6 x 10’ end-to-end
-- PT available in 20 ft lengths
-- Spacing app. 12” between rafters
-- Notch app. 2 1/4 inch at each beam
-- Anchor with screws through top of rafters into beams, predrill?

Purlins 2 x 2 x 8’
-- (2) 8 footers end-to-end to span rafter width of 16 ft
-- Anchor with screws through top of purlins into rafters, predrill?
-- Spacing (tbd) app. 3 to 5 inches
-- Cedar and PT available in 2 x 2 x 8

Questions:
1.Beams 2 x 12 x 20’ PT, 16 span – ok or overkill?

2.Cedar beams option – any practical way to span 16 ft with 2 x 8s? e.g. end-to-end double thick (screw/glue 2 boards length wise)

3.Is Douglas Fir a practical alternative (primed and painted)?

4.Rafters, span app. 8 ft – 2 x 6 vs. 2 x 8s?

5.Rafters if PT – using screws through top into beams plus purlins sufficient to minimize warping or is blocking required between rafters?

6. Plug countersunk screws – what type of caulk should be used (paintable silicone)? (or) epoxy?

7. Any and all other comments/suggestions very much appreciated!!

I really appreciate any help!! :)
 

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You might try submitting the plans to the building dept to check them out.
Ron
 
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