How to build a Spa Gazebo with Bar by Les Kenny
Made out of rough wood, inexpensive to build, and looks awesome!
My son was about to get a new family spa pool and asked if I would build a gazebo to match the surroundings.
It would have to comprise of inexpensive materials, have a rustic exotic look about it, and look good.
And a bar.
Actually, It’s a type of structure I love doing and a rustic look more-or-less comes by default simply by using rough sawn wood, which is also the cheapest of lumber as it hasn’t had to go through the process of being dressed (planed, smoothed, dimensioned).
And a bar that matches? A piece of cake.
So there you are! All the required requisites.
About the length measurements given in this project
All length measurements in this project are given in both inches (standard) and metric (mm).
The standard (inch) measurements are given first followed by the metric equivalent in brackets. For example: 4″x4″ (100mm x 100mm).
This is a rustic looking square gazebo constructed out of rough wood (before the wood has been planed, dressed, etc) and is well suited placed amongst trees and plants in a bush-like setting.
It is 8ft (2400mm) square with an overall height of 110-1/4″ (2800mm) and a clearance of 80-3/4″ (2050mm) from the ground to the lowest part of the roof.
It was made to house a 251 US gallon (950 litre) family spa 79-1/2″ (2020mm) square by 30″ (760mm) high.
It consists of 4″x4″ (100mm x 100mm) corner posts, 2″x4″ (50mm x 100mm) and 2″x3″ (50mm x 75mm) roof framing, and 1″x6″ (25mm x 150mm) roof boards with a plastic glass skylight.
All the wood is rough sawn and the sizes are common and should be obtainable in most places.
The construction steps – a pictorial overview
Above: Putting in the posts and adding the beams
Above: Fixing the gazebo rafters and purlins
Above: Fixing the roof boards
Above: Adding the gazebo bar and skylight
Above: The skylight from under, and the finished gazebo
Materials you will need
All lumber is rough sawn. I.e. before the wood has been dressed, dimensioned, or planed. The list allows for a bit of wastage.
4″ x 4″ (100mm x100mm) ROUGH SAWN TREATED:
Posts: 4 @ 9ft (2700mm)
2″x4″ (50mm x 100mm) ROUGH SAWN TREATED:
Beams:4 @ 9ft (2700mm)
Braces: 4 @ 3ft (900mm)
2″x3″ (50mm x 75mm) ROUGH SAWN TREATED:
Hip rafter: 4 @ 78″ (2000mm)
Purlins: 4 @ 65″ (1650mm), 4 @ 30″ (760mm)
Bar: 6 @ 8ft (2400mm)
Bar brace: 2 @ 16″ (400mm)
1″x6″ (25mm x 150mm) ROUGH SAWN TREATED:
Roof boards: Overall 230ft (70m). When ordering get the longest possible lengths and when cutting, always cut the longest pieces first to avoid wastage.
4.5lb (2kg) of 3-1/2″ (90mm) galvanized flat head nails
4.5lb (2kg) of 2-1/2″ (60mm) galvanized flat head nails
GALVANIZED THREADED ROD
3 pieces of 1/2″ (12mm) galvanized threaded rod 12″ (300mm) long with 6 nuts and washers.
To hold the bar pieces together.
PLASTIC GLASS (ACRYLIC SHEET)
1/8″ (3mm) thick, 1 piece @ 3ft (900mm) square.
A thick type exterior wood glue
Misc You will also need a few assorted screws and some sort of strap metal strips or nail plates to help tie the beam corners, collar ties and rafter apex.
Step one – Set the posts
Set the posts as shown in the drawing below. The posts will form a true square if:
• The posts are spaced apart equal
• The posts are plumb
• The sides are parallel
• The diagonals are equal
Ensure the above requisites are met to avoid possible roof headaches.
The post hole depth (or any other holding method) is not that important. It mainly serves to hold the post in position until the beams and braces have been fixed in place. It is the beams and braces that hold the structure rigid.
Step two – Fix the beams and braces
Trim the tops of the post level, 85-3/4″ (2176mm) off the ground. Referring to the plans, cut and fix the 2″x4″ (50 x 100mm) beams flush with the tops of the posts. Cut the 8 braces and fix them in place. Add a metal strap or similar fixing to the corners for additional holding. See the picture below.
Step three – Put up the rafters
Cut 4 rafters as per plan in the roof plan drawing. 2 @ 72-1/2″ (1842mm), and 2 @ 71-1/2″ (1816mm), A and B respectively. Make up one truss as shown in the drawing above comprising of two rafters (A) and a collar tie (C).
Place and fix the ‘truss’ on top of the posts and then add the other two rafters at right angles joining at the apex. Fix the rafters at the apex and at the corner posts.
Step four – Put in the purlins
Cut four upper purlins at 27″ (685mm) long to the longest points, and four lower purlins at 64″ (1630mm) long to the longest point.
The angle: The ends of the purlins require a compound cut. A compound cut consists of two angles – A bevel angle and a miter angle. In this case the angle across the top of the wood (the miter angle) will be 42.1° , and the bevel (the blade tilt) will be 17.7°.
See the next section ‘Cutting the angles’ for more information
Once cut, fix them in place between the rafters according to the plans, although it will become obvious where they go. Ensure the upper and lower purlins are parallel to each other and the beam.
Cutting the angles
Both the purlins and the roof boards require a compound cut.
A compound cut consists of two angles (off square) in one cut – A miter and a bevel.
In this case, the miter angle is 42.1° off square. That is the angle across the top of the wood.
The bevel angle is 17.7°. That is the angle you tilt the blade on your saw to make the cut.
Set the blade on your saw to 17.7° for both the purlin and the roof board cuts.
Step five – Put on the roof boardsThe roof boards are 1″x6″ (25mm x 150mm).
Start the first board in the middle of the sides. It will be 51″ (1300mm) long.
Have the top a little above the top purlin and the bottom should run past the beam approximately 12″ (300mm).
Once the boards come up to the corner rafters, the tops of the boards will have to be angled to suit. Refer to the previous chapter for the angles.
Fix a temporary straight edge to the rafter giving something to align the tops of the angle cut boards to.
The relevant side of the temporary straight edge must be in the middle of the rafter.
When you get down to the very lower corner (the boards protruding past the beam), there will be nothing to nail those boards to so they will have to be glued in place.
Will the boards be waterproof?
There may be a drip or two simply because the boards are placed together and not sealed in any way.
There will be the odd gap due to movement caused by weather.
Most water directed at the joins will run down the boards (capillary action) but some runoff may get redirected by the purlins causing a drop or two.
The people I built the gazebo for, found it to be no problem at all (having used it for over six months at the time of writing, and at times in huge downpours).
However, if you want the gazebo for another use other than a spa, and you require total shelter – then simply fix a narrow batten over each join such as shown in the drawing below.
Step six – Build the bar
Using six 8ft (2400mm) lengths of 2″x3″ (50mm x 75mm) lumber, do the following…
• Mark the drill holes along the center of each piece – one 6-1/2″ (165mm) in from each end. And one in the middle.
• On two pieces only (the outside two pieces) drill starter (countersink) holes 1-1/4″ (32mm) diameter, to a depth of 5/8″ (15mm) to house the washers and nuts. Continue through the wood with a 9/16″ (13mm) drill bit and do the rest of the holes with that.
• Glue and join the pieces and hold them in place with clamps.
• Using 3 lengths of 1/2″ (12mm) galvanized threaded rod, put a washer and nut on one end of each and thread them through the holes. Add a washer and nut at the other end – and tighten them. Sand the top of the bar when the glue has dried.
• Cut out the two corners on one side to fit the posts, and round the opposite corners.
• Fix it in place 39-1/2″ (1000mm) from ground to the top, and fix the two end braces as show in the drawings.
Step seven – The skylight drawings
Looking down view
Step seven – The skylight instructions
Referring to the previous step-by-step pictures
Pic 1.: All ready to commence making the skylight.
Pic 2.: Fix a strip of wood [a] the same thickness as the roof boards (it can be a ripping off a roof board) to the top of the rafters.
Pic 3.: Measure for the skylight acrylic sheet (plastic glass) [b]. The side edges will overlap the rafters by 1/2″ (12mm) and the bottom edge will overlap the roof boards about 1″ (25mm).
Once you have measured for one piece, the other three should be the same but check just in case.
When cut, put them in place and hold with 2 screws [c] along the bottom edge. Predrill the screw hole in the acrylic sheet and ensure the hole is bigger that the screw shank. Refer to the pictures for placement.
Pic 4.: Cover the gap between the acrylic sheets (over the rafters) with a strip of wood [d] on top. It can be a ripping off a roof board but ideally a strip about 3/8″ (10mm) by 1-1/2″ (38mm) wood look the best. Fix it with three screws [e] spread along the length as shown in the picture. Do not over tighten the screws.
There is no nailing detail for individual steps, but in general, use 2-1/2″ (60mm) galvanized flat head nails for the roof boards (2 at each meeting, placed 3/4″ (18mm) from each side), and use 3-1/2″ (90mm) galvanized flat head nails for everything else. Nowadays a lot of people prefer nail guns or screws and in most cases they would have their own fixing preferences.
All wood is treated and rough sawn.