Lean-to porch roof attachment

Daniel Webb · 11-01-2018, 12:08 PM

The fascia board is a 2x6 and I’m hoping I can attach my 2x6x8 roof joists straight to the fascia using joist hangers.
But I’ve been researching and am seeing people putting ledger boards up first. Is the ledger board a must? If the ledger board is a must can I attach with lag screws or does it have to be bolted? Thanks for your help!

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**Jerry Peck** · 11-01-2018, 12:26 PM

Originally Posted by Daniel Webb

The fascia board is a 2x6 and I’m hoping I can attach my 2x6x8 roof joists straight to the fascia using joist hangers.
But I’ve been researching and am seeing people putting ledger boards up first. Is the ledger board a must? If the ledger board is a must can I attach with lag screws or does it have to be bolted? Thanks for your help!

The two options have the same drawback: how is the 2x6 fascia attached to the structure?

With nails into truss or rafter tails is the most likely method of installing the fascia ... and nails are not suitable for attaching a ledger board or hangers for the shed roof.

This is the scenario: Roofs (and ledgers) are not nailed to the structure for other roofs or decks as the nails can ("will" and "do", forget the "can" part) pull out, allowing the attached roof or deck to come crashing to the ground.

With a fascia which is nailed to the structure ... the same thing can happen, except that it will be the fascia which pulls loose and goes crashing to the ground with the roof or deck.

Daniel Webb · 11-02-2018, 04:57 AM

Originally Posted by Jerry Peck

The two options have the same drawback: how is the 2x6 fascia attached to the structure?

With nails into truss or rafter tails is the most likely method of installing the fascia ... and nails are not suitable for attaching a ledger board or hangers for the shed roof.

This is the scenario: Roofs (and ledgers) are not nailed to the structure for other roofs or decks as the nails can ("will" and "do", forget the "can" part) pull out, allowing the attached roof or deck to come crashing to the ground.

With a fascia which is nailed to the structure ... the same thing can happen, except that it will be the fascia which pulls loose and goes crashing to the ground with the roof or deck.

Thanks for your response.

So can I overcome this problem with simply running a couple screws through the fascia board at each roof truss? Or do I have to take the fascia board down and tie in to the sides of the trusses?

**Jerry Peck** · 11-02-2018, 05:41 AM

Go to a local lumber company (not a Big Box store) as they likely have or can get a Simpson Strong-Tie catalog, and would have a Simpson representative to contact if nothing is shown listed for that use.

Simpson makes many structural connector screws. Maybe they have a structural connector screw which would work in a toe-nail fashion to work attaching the 2x6 fascia to the truss/rafter tail.

https://www.strongtie.com/products/g...s/strong-drive

**Roy Lewis** · 11-02-2018, 07:47 AM

Originally Posted by Daniel Webb

The fascia board is a 2x6 and I’m hoping I can attach my 2x6x8 roof joists straight to the fascia using joist hangers.
But I’ve been researching and am seeing people putting ledger boards up first. Is the ledger board a must? If the ledger board is a must can I attach with lag screws or does it have to be bolted? Thanks for your help!

Before I would start attaching anything to the fascia board I would have to know the load of the new roof addition. Fascia boards are not usually designed to carry much load.

Daniel Webb · 11-02-2018, 08:26 AM

Originally Posted by Roy Lewis

Before I would start attaching anything to the fascia board I would have to know the load of the new roof addition. Fascia boards are not usually designed to carry much load.

Thanks for all of you guys help.

**Garry Sorrells** · 11-02-2018, 08:47 AM

Concerned about knotching of rafter at wall top plate.
Rafter extension going to facia is reduced but not critical since only holding facia board and gutters.

Just a thought.
It is all about engineering for attachment and load

**Egbert Jager** · 11-03-2018, 10:52 AM

Originally Posted by Garry Sorrells

Concerned about knotching of rafter at wall top plate.
Rafter extension going to facia is reduced but not critical since only holding facia board and gutters.

Just a thought.
It is all about engineering for attachment and load

I'm with Garry, the rafter tails (whether from true rafters of the protruding ends of trusses as we see here, was never intended to carry the load of a porch roof. Attaching a 2x6 (or even a 2x4) joist to a piece of wood attached to the tail end of a cantilevered piece of 2x4 is certainly not recommended with the snow loads out here!

**ROBERT YOUNG** · 11-03-2018, 12:12 PM

Daniel, you would be using the eave fascia as a ledger and that is not a good idea.

I would start the porch roof translation atop the original roof above the wall assembly. The wall takes the load. Placing added load at the ends of a rafter may cause rafter splitting when dynamic loads are applied.
Just my 2 cents.

**Jerry Peck** · 11-03-2018, 03:46 PM

What are the snow loads in AT?

What is the frost depth there too?

If it's not "free standing", the bottom of the exterior post footings needs to be below frost depth.

I guess my attempt at pointing out the problems with the attachment of the fascia went over with a thud, as did my attempt to get him to contact a supplier (who would be aware of local conditions) and to have them contact Simpson (for professional advice) likewise went over with a thud ...

**ROBERT YOUNG** · 11-04-2018, 01:06 AM

Originally Posted by Jerry Peck

What are the snow loads in AT?

What is the frost depth there too?

If it's not "free standing", the bottom of the exterior post footings needs to be below frost depth.

I guess my attempt at pointing out the problems with the attachment of the fascia went over with a thud, as did my attempt to get him to contact a supplier (who would be aware of local conditions) and to have them contact Simpson (for professional advice) likewise went over with a thud ...

No, Jerry. Your point to the hypothesis, question, extending roof rafters while changing roof slope to add on a porch roof, needed a tad of reflection, to which you acknowledged. Poignant reflection. An absolute refreshing quality may I add. Always enjoy how you think. Refreshing.

Not knowing the architecture of the structure Danial wants to build is the hypothetical.

Can this extension be performed at/on/to existing rafter ends as you prescribed, with strong ties, Yes. But it may entail 'to much' additional mathematics, geometry, carpentry and materials. IE; Time and Money!

On wider porches I heen it workout leaving a colonial style ranch affect, bracing timbers under the eave, below rafters spaced ><' feet apart, and when amateurly installed, the failings. Split upper rafters and bowed/arched rafters and sheathing. Just drive down some rural roads and look at some homes:-)

Daniel, the term is called over framing. Over frame the porch roof atop the existing roof. Not that complicated. I have performed this type of framing several times in my hay day. Typically you want to use the wall assembly as the lever but you have not provided any photos or plans to use as a visual template.

Here is an image.

**Jerry Peck** · 11-04-2018, 06:15 AM

Originally Posted by Jerry Peck

What are the snow loads in AT?

I just noticed the typo ... "AT" should be "AR", I was typing on my phone and autocorrect kept changing it ... "I thought" that I corrected each time it switched - but autocorrect was sneakier than I thought.