Best option for covering a deck floor that has been enclosed to make a porch?

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alavaliant

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#299347 31-Aug-2022 15:17

My house has a section of deck which has had a roof/walls built around it to create an enclosed porch. I'm not happy with the deck 'floor' as it is however since plain deck planks with the space between them is very drafty.

As a temporary measure I did lay some wooden boards over the decking, which was enough to stop wind blowing up between the decking. But it was loose and is now getting damaged since the wood wasn't rated for water exposure (there is a dog door at one end and water also gets in if you open the doors at the end of the porch during storms).

The image below shows the inside of the porch area. With the temporary wooden panel covering on the left. And the underlying decking 'floor' on the right where I've pulled up one of the wooden panels.

I'm trying to decide how best to give it a more permanent floor that will be wind proof and able to deal with water getting on it.

Best idea I have so far. Is to do a second layer of decking planks, but offset vs the existing decking boards, so they go over the gaps between the existing boards. That would cover the gaps the winds comes through, and the decking boards should be rated for water exposure. - I'm just not sure if having two layers and trying to avoid leaving any direct gap going down (to block wind) is going to cause any long terms problems I've missed?

Does anybody have any alternative/better suggestions on how to handling flooring in this sort of situation?

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#2961587 31-Aug-2022 15:50

Best thing I can think of is install tiles over the floor - won't add much more height than the wood, will look tidy, easily cleaned and should wash off readily too. Heck - you could even pop a drain hole in the corner to splash some water on for cleaning up, and treat it as an intermediary wet room.

Anything I say is the ramblings of an ill informed, opinionated so-and-so, and not representative of any of my past, present or future employers, and is also probably best disregarded.

mattwnz

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#2961588 31-Aug-2022 15:54

If water is getting in, then a deck is and an airflow is needed to make sure it all drys out. You could go for plastic decking. Really you need to stop any water getting in and from the photo it looks like you are getting water tracking in under the door sill frame and into the corners. Is that door frame just sitting on top of the decking timber?

mattwnz

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#2961591 31-Aug-2022 15:56

toejam316:

Best thing I can think of is install tiles over the floor - won't add much more height than the wood, will look tidy, easily cleaned and should wash off readily too. Heck - you could even pop a drain hole in the corner to splash some water on for cleaning up, and treat it as an intermediary wet room.

If water is tracking under the door frame between the deck and the door frame, then water could get between the decking and tiles, and rot out pretty quickly. Plus you need a good substrate for tiles

toejam316

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#2961592 31-Aug-2022 15:58

mattwnz:

toejam316:

Best thing I can think of is install tiles over the floor - won't add much more height than the wood, will look tidy, easily cleaned and should wash off readily too. Heck - you could even pop a drain hole in the corner to splash some water on for cleaning up, and treat it as an intermediary wet room.

If water is tracking under the door frame between the deck and the door frame, then water could get between the decking and tiles, and rot out pretty quickly. Plus you need a good substrate for tiles

Very true - didn't think of that factor at all.

Anything I say is the ramblings of an ill informed, opinionated so-and-so, and not representative of any of my past, present or future employers, and is also probably best disregarded.

alavaliant

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#2961610 31-Aug-2022 16:20

mattwnz:
If water is getting in, then a deck is and an airflow is needed to make sure it all drys out. You could go for plastic decking. Really you need to stop any water getting in and from the photo it looks like you are getting water tracking in under the door sill frame and into the corners. Is that door frame just sitting on top of the decking timber?

The door frame is just sitting on top of the decking timber. Thanks, I never considered water coming under it. I was just assuming it was coming in the door when open or the dog door hole.

Will have a closer look at the join between the door frame and the decking later on. I guess if the grooves of the decking are unfilled with anything, I could add a filler to the grooves to try to better seal things against water flowing under ?

neb

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#2961693 31-Aug-2022 18:31

alavaliant: Will have a closer look at the join between the door frame and the decking later on. I guess if the grooves of the decking are unfilled with anything, I could add a filler to the grooves to try to better seal things against water flowing under ?

Before you do that I think it's important to figure out where the moisture is getting in. Worst case, if you seal up some gap, is that you're sealing the moisture in rather than out and accelerating any rot.

Journeyman

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#2961731 31-Aug-2022 23:02

Get a builder to do it properly.

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Handle9

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#2961733 31-Aug-2022 23:34

Is the bottom plate laid straight onto the decking or is the decking cut and butted up to the plate?

It looks like a classic illegal sh1tshow.

alavaliant

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#2961747 1-Sep-2022 07:26

Journeyman:
Get a builder to do it properly.

I'd love to, but it seems to be such a small job (porch is only 1.5m x 2m). That I've tried and failed multiple times to get a builder interested in the work.

alavaliant

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#2961764 1-Sep-2022 08:58

Handle9:
Is the bottom plate laid straight onto the decking or is the decking cut and butted up to the plate?

It looks like a classic illegal sh1tshow.

Bottom plate is laid straight onto the decking. That's illegal? - I'm a bit confused by that. The porch was originally just a single wall and roof (which came with the house when I bought it), and I had a professional builder add in the doors/windows in the aluminum frame on each end to make it an enclosed porch. - Can't give you too much detail about the work though, that was done about 10 years ago and my memory back to then is a bit fuzzy.

Should also note that my 'temporary' floor covering has been in place for 5+ years, and was until recently covered by some loosely laid vinyl flooring. So the moisture isn't something that has come in quickly. Which I think I may have incorrectly given the impression of based on other posts?

Bung

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#2961829 1-Sep-2022 10:45

The grooves on the decking will allow water under the bottom plate. It might be possible to add another joist under the deck outside the wall line so you can cut the external decking and add some flashing to the bottom of the wall to cover the bottom plate.

alavaliant

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#2961869 1-Sep-2022 12:05

Bung: The grooves on the decking will allow water under the bottom plate. It might be possible to add another joist under the deck outside the wall line so you can cut the external decking and add some flashing to the bottom of the wall to cover the bottom plate.

Thanks for the suggestion. That does seem like a good idea. However that sounds like it would be quite an involved change to make (and I suspect might be a little beyond my DIY skills).

blackjack17

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#2962005 1-Sep-2022 13:53

https://www.tradetested.co.nz/p/home-outdoor-living/outdoor-decor/outdoor-deck-tiles/artificial-grass-deck-tiles-35mm-pack-of-12

https://www.tradetested.co.nz/p/home-outdoor-living/outdoor-decor/outdoor-deck-tiles/outdoor-ceramic-deck-tiles-taupe-pack-of-10

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alavaliant

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#2962087 1-Sep-2022 15:37

blackjack17:
https://www.tradetested.co.nz/p/home-outdoor-living/outdoor-decor/outdoor-deck-tiles/artificial-grass-deck-tiles-35mm-pack-of-12

https://www.tradetested.co.nz/p/home-outdoor-living/outdoor-decor/outdoor-deck-tiles/outdoor-ceramic-deck-tiles-taupe-pack-of-10

Thank you, I am liking the look of those. From my reading on them so far. It looks like they might be ideal for my use case as it looks like I could lay them but easily lift them back up to check on the state of the decking under them from time to time.

Handle9

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#2962226 2-Sep-2022 05:44

alavaliant:
Handle9:
Is the bottom plate laid straight onto the decking or is the decking cut and butted up to the plate?

It looks like a classic illegal sh1tshow.

Bottom plate is laid straight onto the decking. That's illegal? - I'm a bit confused by that. The porch was originally just a single wall and roof (which came with the house when I bought it), and I had a professional builder add in the doors/windows in the aluminum frame on each end to make it an enclosed porch. - Can't give you too much detail about the work though, that was done about 10 years ago and my memory back to then is a bit fuzzy.

Should also note that my 'temporary' floor covering has been in place for 5+ years, and was until recently covered by some loosely laid vinyl flooring. So the moisture isn't something that has come in quickly. Which I think I may have incorrectly given the impression of based on other posts?

I’m guessing you didn’t get building consent?

If it was being done properly, regardless of the consent situation, you would have cut the deck out and built out the floor structure. This would have likely involved extra piles. Once the joists were in place the floor would have been put in place and the bottom plate.

None of that happened and now you are putting lipstick on a pig.

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