Deck Joist Support Question

[Meanie]

I am removing a 46" x 52" corner section of my deck in order to install a central AC unit. I cut the top boards, exposing the joist. I have to remove

3 joists and thus, where my problem lies. I uploaded pictures for better understanding.

>> My thought is attaching a joist hanger perpendicular to the existing joist where the arrow is pointing to in this photo and the another hanger to the cement part of the house. My concern is, can I drill into the cement block of the house or does it hinder it's integrity?

Any other suggestions appreciated.

Thank you

[DD_BobK]

into the cement block of the house or does it hinder it's integrity

[Meanie]

I'm partial to using chemical anchors, SIKA, Rapid Set, etc "epoxies". I like them better than mechanical anchors as their installation stresses the concrete less.

Your deck appears to very nearly sit on the ground. Why remove the section of deck? A few strategically location "supports" between deck framing & the earth should easily handle the weight of the unit.

cheers Bob

I think it's block but uncertain.

I prefer to have the unit seen as little as possible but I also take into consideration of any work is may be required in the future and could involve those joists. If for some reason they ever need to be removed, that unit would be on top and creating more work.

Thanks for the input

[clare]

I say deal with it then, if it is a problem. I wouldn't "butcher" the deck now - and the unit will work better on top of the deck than it will partially hidden by the deck. You need good airflow - and it will be easier to keep clean up on top too. I put my replacement outside unit up on a course of concrete blocks to get it up, high and dry and easier to work on.

[Meanie]

I agree. If anything I would think having the AC stuck part down in a deck hole is just going to draw more attention to it. There is also the issue of airflow being restricted, not a good thing. It also seems a piss poor place, as who wants the noisy AC running and blowing hot air on a deck that you want to use? Isn't there any other place the unit can be put? It's just an issue of running the lines from the air handler and running an electrical circuit. A 50ft set of lines costs maybe $200. They can be run up to about 100ft if necessary. Just saying, I sure wouldn't put it there unless there was no other option.

There isn't any other option. They came, they saw, they advised....that is the best spot. It's the very corner rear of the house.

[Meanie]

Besides, it's roughly 6 to 8 inches below the deck and they will most likely reduce that when they put it on a base. That's not a major restriction of airflow.

[Meanie]

I took the plunge and added the cross support, but the good news is, I only needed to remove two joist and kept the one closest to the house. Therefore, I used it and the other joist as my new hanging points for the cross joist. The opening is a square 46" x 46" and the unit is roughly 3' x 3'.

Thank you all for the input

[clare]

Or any advantage to cut the deck.

[Doug]

A moot point now but I wouldn't want an A/C unit sitting on the deck for a couple of reasons. I think you got it right.

[DD_BobK]

And what would those reasons be? Please enlighten us.

cheers Bob

[krw]

A couple that quickly come to mind; takes valuable deck space, noise (with the deck being a sound board), heat. I'm sure people can come up with some more with a little thought.

[Stormin Mormon]

The vibration of the running unit would be noisy, the principle of a sounding board. I learned that concept years ago, with music boxes.

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.

And what would those reasons be? Please enlighten us.

cheers Bob

[Doug]

Why? Another debate?

[trader4]

Ditto that. I don't see the obsession to cutting the deck and sinking the AC 8 inches into the deck.

As to the they came, they saw, they advised, I would not necessarily believe what one AC company told me, which is there is no other option. Often they want the easy path and don't want to consider options that make it more costly, more work.

[trader4]

ote:

Agree with the above. But the OP still has those issues with what they are proposing to do, which is cut an opening in the deck so the AC sits inside it, about 8" down.

[clare]

Vibration is easily solved with proper mounts - I can't think of any others.

[Doug]

Dont want to consider options that cost more... hmmm, that doesn't sound right if I want someone's business. Last, how many A/Cs have you seen built on a deck?

[Tony Hwang]

Hmmm, How are you going to work on it when needed?

[trader4]

l.me...

The issue is that a lot of guys would rather bid $3900 on a straightforward, simple job, win it, do it, and move on to the next similar job. The alternative, of having a more complex install where they could run into problems that slow them down, cost them more money, etc may not appeal to them.

Also, who goes out to bid on the job? Lots of AC companies send a guy that just does the bidding. He'd probably rather bid a simple $3900 job than waste a lot of time figuring out a marginall higher priced job that doesn't net him much more personally, if anything. And that assumes that the homeowner picks that company to do the job. IF they don't then the guy giving quotes just spent extra time engineering a solution where they don't get the business.

I don't recall any, probably because having it in that location, whether it's on a deck or in a hole with the deck adjoining it is a piss poor location.

[jamesgangnc]

ail.me...

I agree. Location is not all that suitable. All outside units generate a fair bit of noise plus hot air. I would not want one next to my deck, never mind in a hole in my deck. I guess the OP is gone but it would have been nice to hear a logical explanation as to why the unit could not be somewhere else yet still next to the house.