Advice needed - Porch canopy build

[Picalilli]

Hi all,

I’ve decided to take on a project to rebuild the porch canopy on the house and would like to build it so it matches the other original ones on our street. I’ve attached a photo of the originals.

I’m going to build it in sapele and have made a start planing and thicknessing to 60mm square, but now I need to decide on the joinery before I go any further.

The main joint that’s causing me trouble in the one I’ve circled red on the drawing. My initial thought was to go with drawing A, with a mortise and tenon to attach to the top and bottom and a then use pocket screws to attach the cross rail between the brackets (this would have the added benefit of slowing the brackets to be put up one at a time too) …but now I’m wondering whether for strength the cross rails should be tenoned in too, a bit like drawing C.

This will leave the problem of fixing the curved piece in, but in the originals (I have the one the neighbour took down because it was rotting) the curves weren’t actually tenoned in place at all either end - just nailed in with a few big cut nails. Is it the case that the curve here isn’t really doing a lot of work and more decorative, so I don’t need to worry about it being tenoned in? I suppose their way of doing it lasted 100yrs, so should be good, but I’m reluctant to start just hammering nails in. Wooden nails and glue maybe?

I may be over worrying this, but wanted to start a thread and hopefully get some advice generally on this build and post some updates and get some advice as I’m working through it, as it’s the first thing I’ve tried to build without any specific plans to work from.

I’ve also attached a photo of what we have in place now, which is just a couple of diagonal struts and pvc cladding.

The original supports are still in place that they rest on these are stone and set into the brickwork.

Any thoughts, advice would be gladly received. Particularly on best joints to use for the various sections.

 

[johnnyb]

if I were building that I'd try and eradicate as many joints as possible.
the trickiest bit will obviously be the curved supports. I'd attempt to make those in one making it 10 pieces plus things in the middle( turnings and harp pieces.)

 

[Jacob]

It's simple. Dismantle the old one and copy every detail with the new.
Or if it's gone then copy one of the others, exactly.

 

[Picalilli]

if I were building that I'd try and eradicate as many joints as possible.
the trickiest bit will obviously be the curved supports. I'd attempt to make those in one making it 10 pieces plus things in the middle( turnings and harp pieces.)

Do you mean use mechanical fixings where possible rather than traditional joints? I’d assumed that mortise and tenons etc would be better. The curves will be cut from one board (this is also how the original was done). I’ve tried to choose boards that have some sloping grain in the hope of getting as much long grain in the curve as I can. See photos to see what I mean.

 

[Picalilli]

It's simple. Dismantle the old one and copy every detail with the new.
Or if it's gone then copy one of the others, exactly.

No complete old one unfortunately. I have the remnants of the neighbours rotted one that came down, and as I say they originally seem to have just nailed the curve on. I guess if it lasted that long it should be fine? Was unsure about just nailing that part in place though.

 

[Sachakins]

Can't see any reason not to m&t the curved sections.
Yes the old one may have been nailed, but don't confuse it being old to mean its well made.
It may also have been made down to a price.
You have the opportunity to make it up to a quality piece.
Unless your looking for 100% replication of original I'd go with jointed connections and an improved product to boot!

 

[johnnyb]

I mean make it as well as possible but not over make it. it's just I don't like all those mortice and tenons. they are a bit clumsy. if you could make the curve and the bit above in one piece it makes all those redundant. that nailed joint at the bottom could be chopped into the rear strut at an angle rather than a full mortice and tenon. the top two pieces then need wedged through m and ts to resist.(or screws)

 

[toolkit]

Hi all,

I’ve decided to take on a project to rebuild the porch canopy on the house and would like to build it so it matches the other original ones on our street. I’ve attached a photo of the originals.

I’m going to build it in sapele and have made a start planing and thicknessing to 60mm square, but now I need to decide on the joinery before I go any further.

The main joint that’s causing me trouble in the one I’ve circled red on the drawing. My initial thought was to go with drawing A, with a mortise and tenon to attach to the top and bottom and a then use pocket screws to attach the cross rail between the brackets (this would have the added benefit of slowing the brackets to be put up one at a time too) …but now I’m wondering whether for strength the cross rails should be tenoned in too, a bit like drawing C.

This will leave the problem of fixing the curved piece in, but in the originals (I have the one the neighbour took down because it was rotting) the curves weren’t actually tenoned in place at all either end - just nailed in with a few big cut nails. Is it the case that the curve here isn’t really doing a lot of work and more decorative, so I don’t need to worry about it being tenoned in? I suppose their way of doing it lasted 100yrs, so should be good, but I’m reluctant to start just hammering nails in. Wooden nails and glue maybe?

I may be over worrying this, but wanted to start a thread and hopefully get some advice generally on this build and post some updates and get some advice as I’m working through it, as it’s the first thing I’ve tried to build without any specific plans to work from.

I’ve also attached a photo of what we have in place now, which is just a couple of diagonal struts and pvc cladding.

The original supports are still in place that they rest on these are stone and set into the brickwork.

Any thoughts, advice would be gladly received. Particularly on best joints to use for the various sections.

I've done stuff like that. The box section on each end would be half lap jointed and glued. Then the lateral piece is offered up and glued in place and a 1 inch hole drilled through the lap joint into the end of the lateral bar then screwed in place. Actually you don't need the screws it's just belt and braces. Peg joints are like that in very old buildings all the time

 

[Picalilli]

I mean make it as well as possible but not over make it. it's just I don't like all those mortice and tenons. they are a bit clumsy. if you could make the curve and the bit above in one piece it makes all those redundant. that nailed joint at the bottom could be chopped into the rear strut at an angle rather than a full mortice and tenon. the top two pieces then need wedged through m and ts to resist.(or screws)

Thanks - I did think about chopping the bottom of the curve in as you describe. The top two I was going to draw bore rather than wedge.

I don’t think I have boards at width that will allow me to make the curved sections any longer, so it’s that bottom corner pieces that will cause most concern for me, as it would need 3 M&Ts …I’m not sure if 3 tenons in one corner causes issues with the strength of the joint or is just fiddly to do? It’s 60mm square, so I was thinking it’d have to be 20mm deep tenons on 3 sides…or I suppose I could make the bottom rails slightly broader, say 60x80.

 

[toolkit]

The curved supports are made by scribing a circle on back of wallpaper. Divide into 8 using dividers. Scribe line to centre to give ends. Cut one end at 35 degrees. Cut one piece as a template. Draw onto hardwood and cut out. Join 2 pieces together to make one arc.

 

[toolkit]

You join 2 pieces so you can use the grain the right way for strength. It's easier than it sounds. In fact looking I have 6 arcs standing idle in my workshop.

 

[Picalilli]

The curved supports are made by scribing a circle on back of wallpaper. Divide into 8 using dividers. Scribe line to centre to give ends. Cut one end at 35 degrees. Cut one piece as a template. Draw onto hardwood and cut out. Join 2 pieces together to make one arc.

Thanks - that’s a good technique to know about. i have one of the curves from the old brackets so was going to just trace those and cut out of the 8” wide boards (photo in previous post). Someone else mentioned about laminating two boards with grains in different directions to give more strength but all I have is 80mm thick boards to work with and don’t think my bandsaw would handle the resaw of that! I’m hoping it will be strong enough, especially as that’s what the original was and I’m using sapele rather than softwood as the original was.

 

[Picalilli]

Can't see any reason not to m&t the curved sections.
Yes the old one may have been nailed, but don't confuse it being old to mean its well made.
It may also have been made down to a price.
You have the opportunity to make it up to a quality piece.
Unless your looking for 100% replication of original I'd go with jointed connections and an improved product to boot!

Cheers - this was my thinking too, I’m going to keep the main elements as they were as it seems fairly well made but didn’t want to just start hammering nails in!

My main concern is that bottom corner joint now, whether 3 tenons is too much or what the best approach is. 60mm square is hard to get 3 in, I don’t know whether it’s best to narrow the tenons and stagger them, or go for shorter stubby tenons and have them in line …or something else entirely!

 

[johnnyb]

there are a few ways to make this curve. laminating would be the strongest by a huge margin. but a pain.

 

[johnnyb]

I normally think of drawbridge when something to long or awkward to clamp to. it can also be a bit guessy as to how well it pull to.

 

[toolkit]

That technique was taught to me many years ago. Used to make circles about 6 foot dia all the time. You have to keep the grain lateral cut curve t long and there is a break point. Also if the wood needs to be 80mm finish you do it on 2 x 40 mm and glue together crossing the joins. When we did them they had to stand a pounding in the foundry and hot dry sand. Which they did. Also if its to be painted use whitewood not resinous such as beech or sepele, oak etc. Paint won't stick longn term to resin. In the patternshop we used shellac. A trade finish made from crushed beetle believe it or not. It was a powder we mixed with methylated spirits. It lasts. Some patterns were 100 years old and still had colour on the.

Thanks - that’s a good technique to know about. i have one of the curves from the old brackets so was going to just trace those and cut out of the 8” wide boards (photo in previous post). Someone else mentioned about laminating two boards with grains in different directions to give more strength but all I have is 80mm thick boards to work with and don’t think my bandsaw would handle the resaw of that! I’m hoping it will be strong enough, especially as that’s what the original was and I’m using sapele rather than softwood as the original was.

 

[toolkit]

That technique was taught to me many years ago. Used to make circles about 6 foot dia all the time. You have to keep the grain lateral cut curve t long and there is a break point. Also if the wood needs to be 80mm finish you do it on 2 x 40 mm and glue together crossing the joins. When we did them they had to stand a pounding in the foundry and hot dry sand. Which they did. Also if its to be painted use whitewood not resinous such as beech or sepele, oak etc. Paint won't stick longn term to resin. In the patternshop we used shellac. A trade finish made from crushed beetle believe it or not. It was a powder we mixed with methylated spirits. It lasts. Some patterns were 100 years old and still had colour on the.

The thing with shellac and meths it used to soak right through the timber. You could cut an old pattern and the colour was over an inch deep into the wood.

 

[toolkit]

Thanks - that’s a good technique to know about. i have one of the curves from the old brackets so was going to just trace those and cut out of the 8” wide boards (photo in previous post). Someone else mentioned about laminating two boards with grains in different directions to give more strength but all I have is 80mm thick boards to work with and don’t think my bandsaw would handle the resaw of that! I’m hoping it will be strong enough, especially as that’s what the original was and I’m using sapele rather than softwood as the original was.

Trying to cut out of one board will give you 2 weak points at least. The method below is the way to go and has been for 100 years or more. Lol. Don't use plywood it will delaminate over time. Don't bother with tenons etc it's overkill as someone has already said and it will weaken the joint. Half laps dowel pegs is the wY. If you want belt and braces run a router on top when it's done and let in a piece of strip across the joins. Glue in place and clamp. It will never move.

 

[Picalilli]

Trying to cut out of one board will give you 2 weak points at least. The method below is the way to go and has been for 100 years or more. Lol. Don't use plywood it will delaminate over time. Don't bother with tenons etc it's overkill as someone has already said and it will weaken the joint. Half laps dowel pegs is the wY. If you want belt and braces run a router on top when it's done and let in a piece of strip across the joins. Glue in place and clamp. It will never move.

Hmmm…how would the corner joint work using lap joints if I need to connect 4 pieces, including the curved piece? I am slightly concerned about the curved pieces weak points but encouraged by the fact the original was done in the same way. The timber has been purchased now so I’m sort of committed to that approach. I’m thinking that I could put in a diagonal support further up too (see image) to minimise the work the curved support is having to do.

 

[toolkit]

Hmmm…how would the corner joint work using lap joints if I need to connect 4 pieces, including the curved piece? I am slightly concerned about the curved pieces weak points but encouraged by the fact the original was done in the same way. The timber has been purchased now so I’m sort of committed to that approach. I’m thinking that I could put in a diagonal support further up too (see image) to minimise the work the curved support is having to do.

The half lap and peg is a joint used in patternmaking to make a very strong box section. It would be done on each of 4 corners to produce the box. If I were doing it I wouldn't fit the arc end to the same point but move it inwards about 3 inches. I'm not sure the arc piece is meant to be load bearing see but more a decorative feature. If it were load bearing it would be straight and notched into a back piece. Think of your college days and physics. A curve under load will bulge out at widest arc as that is where the stress is. A load bearer would be straight to transfer the load to the wall where the load would be concentrated.