To LINTEL or not to LINTEL that is the question?

[pzachef]

I am at a point in my build where I need to decide this (before this weekend). I've seen pictures on this site and others where lintels are not used. What is the concensus out there?
I attached two such photo's, I don't remember if it was from this site or not..

[splatgirl]

Re: To LINTEL or not to LINTEL that is the question?

it doesn't matter. If it's going to be covered up with whatever exterior finish you use, make things a little easier for yourself and use one. if that area will always be exposed, then I'd opt for not using one since it looks nicer. And if not using one scares you, there's no reason you couldn't place one piece at the inside edge of the block opening so that it's not visible from the outer, front edge of the slab.

[dmun]

Re: To LINTEL or not to LINTEL that is the question?

Yes, it's a design choice. If it's made of concrete blocks, it really isn't much stronger then the angle iron that holds it up. Besides, the couple of pieces of extra rebar are cheaper than two pieces of angle iron anyway.

[pzachef]

Re: To LINTEL or not to LINTEL that is the question?

I forgot to mention I will be cantalevering a 12 inch landing over the front.
Thanks for the feedback, please keep it comming. Where the photo above stops the slab at the end of the vent landing, I will extend out 12 inches on the angled front.

[pzachef]

Re: To LINTEL or not to LINTEL that is the question?

It's done, I poured my top slab without a lintel.

[cnegrelli]

So I'm wondering if this is still an open question? I've seen builds such as UtahBeehiver and others where the Lintel is a poured arch, with Rebar only. That is an arch design, as opposed to just a poured slab of course. Are there other threads where this is discussed? Is a Lintel with angle iron really adding much and necessary?

[Toomulla]

I presume you are referring to support for the hearth / structural slab. a 100 mm ( 4 inch) slab is more then capable of spanning. the normal 600 to800 wide opening particularly if an extra couple of 12 mm bars are added in the area over the opening. any opening is usually directly below the oven opening so further reducing the load . In general concrete buildings a 200 mm or 8 inch slab spans at least 20 feet or 6 meters.

[cnegrelli]

I presume you are referring to support for the hearth / structural slab. a 100 mm ( 4 inch) slab is more then capable of spanning. the normal 600 to800 wide opening particularly if an extra couple of 12 mm bars are added in the area over the opening. any opening is usually directly below the oven opening so further reducing the load . In general concrete buildings a 200 mm or 8 inch slab spans at least 20 feet or 6 meters.

Great feedback. By 12mm bars, can I assume you are referring to rebar? I was planning 1/2" (so basically 12mm) rebar with extra across the span of the opening.

[Toomulla]

That is correct, the bars across the opening should be in the bottom half of the slab depth