Garage Floor: How to Seal Metal to Concrete

Do you have to worry about it freezing?

Unfortunately I have no suggestion?

More concrete or Grout? Not sure really.

Closed Cell Expaning foam? Messy stuff, you'd have a hard time getting it clean after that for sure...

Yeah...Im in West Virginia...Gets down pretty cold here sometimes...So it has to be flexible...

Im out of ideas...

Have/can you apply expandable foam

j.

I have never even seen this for real but while at FinishMasters (car paint store) I saw an ad for "do it at home" truck bed liner. I don't know if this is as tough as the "rino" stuff, but most modern truck bed liner sprays stick and seal very well. I don't recall the price, but the ad was for a modest amount. I looked at it and thought it was probably too little for a full size pickup (just what I recall). If it is possible to spray through a straw then you will have some mighty tough gap filler.

Something else to consider is the roll on goop for the roof of a mobile home or travel trailer.

I never tried either of the ideas above. When I built my shed I used about 1 gallon of roof tar for every 20 feet of bottom plate and held it down with 1/2" wedge anchors every 32". I don't know how I ended up using that much tar. But, after years of hard rains my only leak issues have been at the door thresholds where I did not use this method. Next time, I'll do this to door thresholds too. (Door thresholds don't get the 1/2" wedge anchors).

Epoxy, especially the stuff made to anchor rebar into a concrete hole. It comes with a small tip and will stick to everything you want it to (and everything else too).

Several times I have mixed up 50 minute marine epoxy from Ace Hardware and put it in a plastic syringe. VERY HANDY. I don't know about adding it to multiple layers of failed attempts, but when you put it in a clean hole things stay attached to concrete.

KC -- Try 3M 5200 marine sealant. Pricey at up $20 a cartridge; but it's near the best you can get. The big boating gear chain West Marine sells it. Shop the internet and you'll find it cheaper. Google "3M 5200 sealant".

Ed Weldon

What about silicone caulk?

ChazL

I'd use plumbers putty they do, could be applied to the inside.

or

Mono-plastic cement could be applied to the inside also known as expanding grout used to seal machine tool bases.

A good quality butyl sealant will do the trick and last. Assure that you clean the two substrates well before applying.

Thanks guys...

That spray on truck bed liner might do the trick, that stuff sticks to anything and its water tight...Might not look the best but its going to be covered up with dirt anyways...

And that marine sealant, can I apply that over my other layers, because like i said, there are 3 layers on there now of tar and silicone and flashing adhesive. It will be a real PAIN IN THE you know what to clean completely.

Since the bed liner spray works really well on metal and on concrete there should be no problem spraying or rolling it along the area where the metal and concrete meet at your garage. You might have to fill in areas that are wider than an inch.

Car under-seal - which is rubber based I believe, is an
exceptional sealant, sticks (very) well, and accepts
movement, expansion and contraction to the weather.

Can be removed easily (with many spirits) it is just a bit
messy that's all. (believe its called "scholts" in a can, but
my spelling may be out.) Can be sprayed; but used with
a putty knife it will make an almost permanent seal.

jt.

ps.. I use it a lot on the top of fence posts, marvelous stuff.

............and I will be covering this back up within the next few weeks.

You may want to reconsider this step if you can avoid it. The french drain may take away the flowing water, but moisture will remain and you will eventually have more than 1/16 inch gap.

It's likely that the sealants your using at letting go of the concrete. Since moisture can permeate concrete, it's probably causing the bond to degrade and fail. I've successfully fixed concrete to concrete cracks using hydraulic cement. I'm not sure if you can use that against metal.

Haven't used it but I've read that concrete specific epoxies can be used for sealing cracks. I'm going to guess the "concrete specific" part is important because I've had bad luck using household epoxy on concrete. I don't think they sell it at Lowes or Home Depot.

I would agree with the hydraulic cement. I have used it to seal core bored penetrations in my foundation, no leaks and I don't have gutters or a curtine drain (house is too old). Also I have had sucess with hydraulic cement and repairing a leaking bulk head, but we did remove the bulk head and rough the concrete then applied the hydraulic cement and reinstalled the bulk head.

I'd take this opportunity (with the foundation exposed) to build a block (or poured concrete) wall to a foot or so above grade. I can't imagine anything that would permanently seal metal siding to concrete on the uphill side of a building, when the siding is underground. The steel siding can be displaced inward by soil pressure enough to shear even a very flexible sealant. In virtually all codes, the siding must be kept at least 6" above grade.

If there are multiple layers of any sealing membranes, the effectiveness is limited to the seal between the first layer and the concrete and steel siding. If that seal is intact, then there is no need for additional layers, and you wouldn't have a leakage problem. If that seal is not intact, then additional layers will do no good, because the water will find its way in through some small opening that gets broken during back-fill, and then seek its own level and fill the space behind the first layer with water, which will then leak into your garage.

This article (http://icf.loyola.com/products/icf/pdf/part12.pdf - sorry, link no longer available) provides some names of various membranes, and also some rules of thumb re drainage. Really good drainage is a key to eliminating these problems. On the uphill side of a structure, the soil must slope away from the structure for at least several feet. The base of the French drain should be well below floor level, so water can build up temporarily without reaching floor level. I think the use of filter fabric all around the gravel is a good idea, to help keep the drain from clogging over time. It's important to make sure that the drain pipes away from the French drain are adequately sloped, and that the openings are guarded against animals crawling in and building nests. A good rule of thumb, I think, is that before filling in the drain, you imagine the water table trying to rise to the level of your floor, and see that the drain is so effective that that cannot happen.

If the uphill side has a lot of clay, this works against you and also for you. Clay is a good sealant against the foundation, but causes water to rush down the hill toward the foundation. Grading away from the structure is essential, and the top of the french drain should be wide, and unobstructed, and definitely not covered by soil containing any clay. Any gutter drainage is best taken well away from the foundation by piping and discharged at a level below the floor.

The day I moved into this house, the lower level floor (where I am sitting right now) was flooded. After redigging the drains and regrading next to the uphill side of the house, routing the gutter drainage away from the house, lining the house side of the french drain with a membrane, and ensuring that ground water would quickly get into the drain, the house has been bone dry -- all without having to reapply any sealants to the foundation itself.

I agree poured concrete with Kryton admixture integral water proofing is an intelligent choice, anything less without a grade correction is guaranteeing future problems and possible litigation if a transfer of ownership or obligation.

Its difficult to get any polimer/caulk to stick if ther is any contaminant on the surface, as a last resort have you ever heard of chinking, a very old method of sealing boats and log cabins, you can use the old materials, but i would try this old method with new materials, rubber tube, weather stripping etc.

Hello Guest,

As an ex builder I have dealt with this problem before. My remedy was to use silicone sealer on the outside and inside of the garage, where the metal sits on the concrete.

If this does not work because of the tar etc. And, if it is a flat sided construction, you could use lead flashing. The same stuff as used on roofs. It is about 200mm (8") wide but, you can get the width you need if you search. Use the silicone sealer under the wooden batten used to hold the lead flashing in place. The flashing should be long enough to direct rain down the side of the garage and over the edge of the concrete base.

An alternative, if the garage structure is solid, is to clean what you can of the tar etc away using a gas torch/blow-lamp to melt the tar, directing the flame down directly onto the steel, use a 'knife' to try and move the tar as soon as it becomes soft. Cut some wood wedges to allow you to lift the whole, or one side of the garage at a time, and you can then lay dense foam sold in sheets or rolls and you cut it to length . Cut the lengths about 10 mm (2/5th") longer than needed, and as you let the garage down so it is sitting on the foam it will make tight joints where the corners meet. ............................If the structure is bolted to the concrete you will need to loosen the bolts enough to allow the thickness of the foam to slide under. Just cut a slot 3 mm (1/8th") to match the placing of the bolts and it will seal OK.

(Good luck and let us know how you get on.

bb

Hey bb,

Good points all, here it comes but the trouble is the exterior wall though not designed as such is being employed in a below grade situation.

Having exterior siding mated to the slab without drains three feet below grade is a no win proposition.

A picture would go along way...

Hi wire,

indeed a picture and detail would be a great help.

My thought was, that the water is going to run off the garage roof whatever type of drainage there is. I assumed in this situation there would be no more water 'shed' than say a similar sized area of 'lawn' would have to soak up?

I know if it was my garage I would wedge it up and clean, then either caulk or lat rubber then slowly pull the wedges out. I have done it so know it works. But, you kinda have to have a 'builders 'nonce', (not sure of the spelling there) which is a bit like an engineer can tighten a bolt until it goes 'plastic' and be able to 'know' that feeling? It is the same with lowering the garage again, slowly does it?

Thanks for the 'hey!

Same back to you my friend.................

bb

This is what I would do..........

1. Clean any debrie out of the joint, Wire brush.

2. Apply a good stone or concrete sealer. several coats

3. Fill the joint with a good silicone caulking compond. smooth caulk with a wet spoon.

I have not tried this on your specific application but it worked well on sealing leaks on my metal celar hatch way door to the cement/brick foundation.

Guest,

Lots of suggestions. Pertinent ones pointed out the problem of additional coats of sealants not working if the first one is bad. Silicones can create problems regarding other sealants not adhering well to it.

A different approach I have seen work is to put powdered bentonite clay against the foundation wall at the time of backfilling. This stuff is very expansive whenever it gets wet, so water that tries to penetrate through cracks will wet this down as it enters the cracks, and the clay will swell up and seal them so there is virtually no leakage. Look for pond sealer in the farm supply stores.

--JMM

Hello jmuellier,

I have not heard of the Bentonite clay before. Sounds like you could be onto a winner?

bb

Its commonly used in lining the bed for wet sediment ponds ether as state above as a powder or in sheets. I know its really good for lining ponds until vegetation starts pocking holes through it. I'm also not sure it it will work with sealing the crack between the metal and concrete but it might be worth a try.

A grout material may do the job. If the grout were applied then sealed it may prevent moisture from being pushed through between the two surfaces.

I would use a polysulfide caulk (Boat Life) or polyurethane. It sticks better than silicone. Use a layer of foundation drain mat (Enkadrain) or crushed stone before you back fill.

Use EPDM to overlap the sill up to about six inches above grade and down and under the drain then back fill and stop dinking around with half baked remedies.