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I have an old deck taken down and the old footing is 3" above the ground but the building code requires 6". Do you have any ideal to increase the height of the footing without replacing it?

Thanks a million.

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    Was the old deck permitted and inspected. ? It could be grandfathered in. Have you asked your local code office ? – Alaska Man May 6 at 20:39
  • To help answer a discussion in comments to an answer: Are you "basically putting the same deck back but with parts replaced, cleaned, fixed, etc."? Or are you designing and installing an essentially "new" deck that happens to be use (if you can) the same footings? – manassehkatz May 8 at 3:56
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I do not know how big they are but one idea is to use a hammer drill and a masonry bit to drill 4 holes in a square pattern about 6 to 8 inches deep, not too close to the sides (three holes would work for a smaller footer diameter).

Place a piece of rebar long enough to make a 6 to 8 inch addition into each hole and wire them so they do not move around. I do not think i would add just 3 inches as that may not hold up, go for at least a 6 to 8 inch gain.

I would grind the tops of the old footers, rough them up or create voids and ridges, and prime them with a concrete patching primer. The rebar is doing the holding but the primer will help make a good bonded seal between old and new to keep out water.

Place a sonotube the same size as the old footer around the old footer (if they are round) or build a form around them if they are square. The form should be about an inch higher than the tops of the rebar. Make sure the rebar will not interfere with post brackets you intend to use.

Now you can pour new concrete and add post brackets.

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    This answer is absent on the proper recommendation on anchoring the rebar stubs into the holes drilled into the existing footing. There are epoxy materials for this purpose. – Michael Karas May 7 at 10:24
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Check a local hardware store for concrete deck blocks or deck piers. They're a pyramid-shaped solid concrete block, about 6-8" tall, usually with grooves in the top for horizontal 2-by-x lumber and 4x4 posts.

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    Eric, what does he do with these blocks ? How do they help raise the footers in question ? – Alaska Man May 6 at 20:48
  • Deck blocks are for floating decks. OP has a traditional deck with footings and a floating deck may not be possible depending on size, height and other factors. – manassehkatz May 7 at 5:10
  • I misread the OP. I thought it was a floating deck that was originally 3"above the ground and needed to be raised 3-4", in which case he could just use taller blocks or replace the posts with slightly longer ones. A neighbor had a similar issue with a deck over a low marshy area in his yard so that's what came to mind. I like your idea of adding a 6-8" lift on top of the existing footers if local code will allow it. Since the old deck was taken down, they may see it as a replacement and require new footings and construction to current code. – Eric Simpson May 7 at 18:47
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You may be able to re-use the existing footing at the same 3” above ground level, if you use the pressure treatment that is rated for “ground contact”. I’d check with your local building department.

Also, the “grandfather clause” is in reference to “repairing/maintenance” of building issues based on their value. Your situation falls within that “clause”.

BTW, you may not need a building permit either...I’d ask your building department.

  • Grandfather clause likely doesn't apply after taking down the old deck. Permits are typically required for decks because the hazards of an improperly built deck falling several feet are so high. – manassehkatz May 7 at 5:13
  • @manassehkatz Actually, there are only two issues that must be brought up to code: 1) safety glass within 18” of a door or 18” of the floor, 2) smoke detectors for sleeping rooms. Everything else can be “grandfathered” if you are replacing the existing. However, the building official can require anything, especially if he determines something is dangerous. – Lee Sam May 7 at 12:13
  • I wouldn't be so sure that "old deck taken down" falls within a grandfather clause. It might, but it might not. There was a recent post about someone using a grandfather clause to keep a garage the same size (and setback) as previously - only way inspector would let him keep it was to literally lift & move entire walls in order to fix the floor - breaking down the walls would have lost the grandfather clause. In addition, we don't know the original footing status - i.e., needed to be taller and were but now sunk (and therefore need to be raised up), needed to be taller but were not... – manassehkatz May 7 at 22:45
  • in which case non-compliant and needs to be totally redone (can't grandfather a violation!), or shorter was OK but the code changed in which case if the rest of the deck , despite being taken down already, can be grandfathered then the existing footings are OK. We just don't know. – manassehkatz May 7 at 22:46
  • @manassehkatz Actually, you can “grandfather” in a violation. For structural work, the existing has to be more than 150% off the current Code before it has to be changed. (ICC Appendix J.) You wont find the word “grandfathered” in the Code. What we all consider grandfathered has to do with “Repair” as outlined in Appendix J of the Code where you do not need to bring everything up to code...unless you’re doing “renovation” or “alterations”. “Repair” is like maintenance. That’s why you don’t need a Building Permit for replacing carpet, roofing, etc. The OP is fine unless he’s upgrading his deck. – Lee Sam May 8 at 3:48

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