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support beam sitting in water - remedy?

Posted by garoj (My Page) on
Sat, Feb 7, 09 at 9:33

A contractor put in a new beam holding up my flat garage roof. It is seriously overbuilt, with 4 16" LVL's. At each end are 6x6 pressure treated beams. He dug out the floor at one end because we deemed it not thick enough and he put in a new footing area. However, that area is both about 1/8" lower than the rest (probably a function of how he put the form when he poured) and it gets water leaking in from the corners of the garage doors (it is right in the middle of two). AT this time of year there is no remedy the water coming in. So, what is the best way to prevent this beam from sitting in the standing water? I was thinking of just waiting until it is perfectly dry and then pour concrete around it, to a few inches up, to seal it. But maybe the concrete will actually absorb moisture? Or maybe do that and sister another beam in front of it on a raised footing? Can I just tar it and then pour around it? Thanks for any help. No, I won't be having the contractor back, and not only for this issue.

Follow-Up Postings:

RE: support beam sitting in water - remedy?

Any wood in contact with concrete belopw the ground surface or within 18 inches of the ground surface needs to be pressure treated.

While concrete may appear dry, it holds and wicks moisture very well.

RE: support beam sitting in water - remedy?

I assume you are talking about 6x6 posts and they should be good for quite awhile since they are pressure treated but they will eventually dry out and crack like any wood. I would replace them with steel posts on a concrete base higher than the floor and with a top plate to transfer the load from the beam. That is what is appropriate for a load of this size. How is a 7" wide beam supported on a 5 1/2" post? Are there through-bolts connecting the LVLs together? Who is the designer of the structure?

RE: support beam sitting in water - remedy?

Thank you brickeyee and mightyanvil. The span is actually 26'. At the time, I checked with the architect at the local building supply and they suggested that for the snow load two of the beams would be sufficient. This contractor gave the dimensions to his architect who said 2-3. He did 4. Not sure the extra weight was necessary, but there you have it. They are held together with the [name escapes me] large screw-bolts, which the town inspector told him for fine for it (he had started with bolts and there are a few).

The 6x6's are indeed pressure treated. I asked about steel posts but he said they were too expensive, but after having him work on several other projects it is conceivable that they were only minimally more expensive and the would nevertheless eliminate them from consideration. A steel post with a plate at the top sounds right and I will approach the architect at the building supply/lumber company, who seemed very good.

How much pressure can 6x6 posts bear?

Attachments: some kind of simpson ties between post and beam; ties to the wall structure (which he beefed up with a row of 2x4's); and the beam has hurricane ties to ever rafter on the roof.

Other suggestions welcome.

RE: support beam sitting in water - remedy?

I can't imagine that architects would be sizing beams for lumberyards or builders unless they are desperate for work and there are no requirements for engineers to provide that kind of information in your state. The builder spent too much money on unnecessary LVLs and then tried to make it up on the posts.


I find it difficult to believe that any design professional would provide information for such a project and not include the design for he posts and top and bottom connections. I strongly suspect that others are pulling your leg about the professional capacity of the designers which is illegal in every state I have practiced in. Someone owes you an explanation.

RE: support beam sitting in water - remedy?

I misspoke. It was engineers, not architects, whom I contacted and whom my contractor supposedly contacted (I overheard the conversations in which he supplied the info, at least).

You are probably correct on the other issue.

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