Pergola build
- Thread starter ihadablackdog
- Start date
Spaldingski
ihadablackdog
Senior member
These are the post bases we got: https://ozcobp.com/product/6x6-post-base-ls/
As you'll see, they are from the US and feckin' expensive! Got them through Amazon and shipped from somewhere in America to here in 6 days. We had 3 of these, and 1 pack of the "s" hangers which has 2 in it.....weighed a tonne, its real heavy stuff.
The centre hole is recessed, and the actual bit that the post sits on is raised a few mm off the ground, so its got a bit of a standoff to help water drain away. A bolt might just fit but it would be tight, hence having to set the chemical bolt carefully...and as you say, thats a faff and doomed from the start. Technically I could just drill a wide hole in the bottom of the post for a recess, but would rather not.
I read somewhere to avoid drilling closer than 4 inches to the edge of the slab.
So those screws have potential. The centre hole is 16mm so i'd need a big washer or see if they do wider screws...looks like 10mm are biggest in that range. The base also has 4 separate holes I could use instead which are 8mm, so would fit perfect, but would I be ok drilling 4 holes so close?
Forgot to say earlier....will take pictures when its done! If I'm happy with it, plenty of pictures! If its sh1t, then probably just one blurry picture
Now I have the actual post bases, if the rain stops, I'm planning to go out this weekend and work out where to put them....possibly even fit them this or next weekend.
As you'll see, they are from the US and feckin' expensive! Got them through Amazon and shipped from somewhere in America to here in 6 days. We had 3 of these, and 1 pack of the "s" hangers which has 2 in it.....weighed a tonne, its real heavy stuff.
The centre hole is recessed, and the actual bit that the post sits on is raised a few mm off the ground, so its got a bit of a standoff to help water drain away. A bolt might just fit but it would be tight, hence having to set the chemical bolt carefully...and as you say, thats a faff and doomed from the start. Technically I could just drill a wide hole in the bottom of the post for a recess, but would rather not.
I read somewhere to avoid drilling closer than 4 inches to the edge of the slab.
So those screws have potential. The centre hole is 16mm so i'd need a big washer or see if they do wider screws...looks like 10mm are biggest in that range. The base also has 4 separate holes I could use instead which are 8mm, so would fit perfect, but would I be ok drilling 4 holes so close?
Forgot to say earlier....will take pictures when its done! If I'm happy with it, plenty of pictures! If its sh1t, then probably just one blurry picture
Now I have the actual post bases, if the rain stops, I'm planning to go out this weekend and work out where to put them....possibly even fit them this or next weekend.
Sounds about right to me. Your posts will be where your posts need to be, so if any are near an edge, just be really careful drilling. As you should be going down through more masonry they should be fine once drilled. You won't break a slab with nylon inserts (plugs) after they have been drilled. If any don't get a good "bite" then maybe go down the chemical anchor route.ihadablackdog said:
Either would be fine as long as you go steady drilling the slabs. The advantage with four holes is you can "level" the holder in four planes with the screws to get your posts as vertical as possible. If you wanted to just put one centrally these penny washers are the way ahead. 6mm hole and 18mm overall.ihadablackdog said:
https://www.screwfix.com/p/easyfix-steel-large-flat-washers-m6-x-1-6mm-100-pack/413ft
ihadablackdog
Senior member
ihadablackdog
Senior member
Decided to go with the chemical anchor system in the end. Doing this way gives me a tiny bit of wiggle room if I’m a smidge out, the screw method would need to be mm perfect to get all 4 holes for the base spot on....and I don’t trust myself.
So fitted the studs today. Got half way through the first hole and my 20yr old hammer drill battery died.....so went and borrowed my neighbours Makita SDS drill....holy s**t, that was like a hot knife through butter! The stuff sets really quick and ready to use in about 3hrs, but I won’t be doing more until next weekend, so plenty of time for it to set.
Hope I did it correctly....too late now
So fitted the studs today. Got half way through the first hole and my 20yr old hammer drill battery died.....so went and borrowed my neighbours Makita SDS drill....holy s**t, that was like a hot knife through butter! The stuff sets really quick and ready to use in about 3hrs, but I won’t be doing more until next weekend, so plenty of time for it to set.
Hope I did it correctly....too late now
ihadablackdog
Senior member
True! Wood should be arriving this week (timber yard dicked me about but came good eventually...as long as they deliver!).
Going to notch the rafters, but the rear notches are going to be 45 degree's, so cant use the jigsaw method unless I plunge cut, which I don't think is a good idea. So going to use the circular saw method on those....however:
Its a 6" board ontop of an 8" board. I was planning on notching out 3" of the top board, but circular saw only goes to just over 2", so do you think 2" will be enough? I could notch out the beam an inch or two, but don't want to risk weakening that, and that would double the number of notches I gotta do...already looking at 30ish!
Going to screw them down from the top, looking at 200mm screws (I bought 140mm but not sure if they are long enough now).
Looks like one of my side studs is about 5mm out. Got some play with the post bases so should be able to rectify, but I'm thinking 5mm shouldn't really mess up the angles, considering the overall size....hopefully I'm just being over critical!
Going to notch the rafters, but the rear notches are going to be 45 degree's, so cant use the jigsaw method unless I plunge cut, which I don't think is a good idea. So going to use the circular saw method on those....however:
Its a 6" board ontop of an 8" board. I was planning on notching out 3" of the top board, but circular saw only goes to just over 2", so do you think 2" will be enough? I could notch out the beam an inch or two, but don't want to risk weakening that, and that would double the number of notches I gotta do...already looking at 30ish!
Going to screw them down from the top, looking at 200mm screws (I bought 140mm but not sure if they are long enough now).
Looks like one of my side studs is about 5mm out. Got some play with the post bases so should be able to rectify, but I'm thinking 5mm shouldn't really mess up the angles, considering the overall size....hopefully I'm just being over critical!
ihadablackdog
Senior member
Thanks. 2” it is then.
Weather looking ok for the weekend onwards so should be good to go!
2nd of my 45 degree angled rafter hanger due today/tomorrow along with various other bits and bobs this week.
I’ll be much happier when I’ve got the posts up and supported.
I’ll be even happier when it’s finished
Weather looking ok for the weekend onwards so should be good to go!
2nd of my 45 degree angled rafter hanger due today/tomorrow along with various other bits and bobs this week.
I’ll be much happier when I’ve got the posts up and supported.
I’ll be even happier when it’s finished
ihadablackdog
Senior member
So it turns out my slabs arent perfectly level, so when I put the post bases in place, they either rock a little off two oposite corners, or when sitting flush, isnt level. Its obviously not major as its a flat patio etc, but I'm not sure if I need to worry.
Obviously I need the bases to be secure and not wobble etc and then when I fit the posts, I have one of those post-spirit level things, but surely if I move the post to be vertical and then screw it in, there will be a small gap between the bottom of the post and the metal plate of the base.
When I watched the videos, they basically say to do this, but wouldn't that put strain on the screws?
The other option is to try and level the base when tightening the bolt by putting washers etc at the corners? I looked at the gripfill but don't think thats meant for this sort of "filling"?
(as you can tell, I'm a complete novice.....hopefully not so novice that it falls down )
Obviously I need the bases to be secure and not wobble etc and then when I fit the posts, I have one of those post-spirit level things, but surely if I move the post to be vertical and then screw it in, there will be a small gap between the bottom of the post and the metal plate of the base.
When I watched the videos, they basically say to do this, but wouldn't that put strain on the screws?
The other option is to try and level the base when tightening the bolt by putting washers etc at the corners? I looked at the gripfill but don't think thats meant for this sort of "filling"?
(as you can tell, I'm a complete novice.....hopefully not so novice that it falls down
)ihadablackdog
Senior member
Timber is here! I love it, lovely colour! I crapped myself when I saw the length of the posts....turns out they gave me 12ft posts rather than 8ft posts as they said the off cuts were no use to them. Think I can use the extra to do some of the corner braces.
ihadablackdog
Senior member
Been thinking about levelling the base supports....think I’m going to try using the fixing screws you told me about as they would make it easier to keep the washers in place.....so the studs might have been a waste of time (they will help though so not really wasted).
Good luck. If you get one post in and plumb in both directions, then temporarily screw pieces of timber at a manageable (head) height to all three posts, you can then plumb the other two easier as it will all support itself as a triangle. You will have to keep checking the first one though. 
ihadablackdog
Senior member
Post bases in and levelled. Most of the day, but worth it due to the importance of these.
Secured with M12 threaded rod and M12 nut, and 4 M8 screws.
Added thread lock to the nut and also covered the top of the threaded rod with it as it resists corrosion.
Secured with M12 threaded rod and M12 nut, and 4 M8 screws.
Added thread lock to the nut and also covered the top of the threaded rod with it as it resists corrosion.
ihadablackdog
Senior member
Pondrew said:Blimey! I don't think you're going to be accused of "bodging it"
Try to do a good job, even though I haven’t a clue what I’m doing, but with your help and YouTube I should be ok
Sanding today and cutting posts to length (I ordered three 8ft post and they gave me three 12ft posts, they said the extra 4ft was no use to them so I might as well have it! Makes them bloody heavy though!
Also got to cut a template for the fancy bits on the ends....an offset 45 degree cut isn’t good enough apparently (according to Deb).
ihadablackdog
Senior member
Want them to be the same as in the video, so thanks for the tip on how to get the curve (although getting the template right is one thing....not screwing up the actual cuts is another!).
So yesterday was slow progress. Had intended to get the 3 posts cut and sanded and the 4 beams sanded and template made.
That didn’t happen! Took me ages to cut the posts with a circular saw as it only goes to about 2.5 inch, so had to cut 4 sides and I just couldn’t get them to meet up! In the end I devised a method that worked for me.
Then onto sanding....belt sanded with 60 grit paper and it still took ages to get the saw marks out, in the end I got 2 of them finished as it was too late to start the 3rd.
So only got 3 posts cut and 2 sanded.
Pictures show 1 sanded and 1 unsanded.
So yesterday was slow progress. Had intended to get the 3 posts cut and sanded and the 4 beams sanded and template made.
That didn’t happen! Took me ages to cut the posts with a circular saw as it only goes to about 2.5 inch, so had to cut 4 sides and I just couldn’t get them to meet up! In the end I devised a method that worked for me.
Then onto sanding....belt sanded with 60 grit paper and it still took ages to get the saw marks out, in the end I got 2 of them finished as it was too late to start the 3rd.
So only got 3 posts cut and 2 sanded.
Pictures show 1 sanded and 1 unsanded.
