So I am installing a short railing approximately five feet long onto a set of church altar steps (to be used by the elderly priests  who have trouble walking up and down them) the dilemma I am having is about deciding which anchors to use as the top face of the floor is marble and supposedly the underside is concrete but no one is really sure and I have a limited time to install the railings. If anyone has any ideas about what anchor to use or could point me in the right direction it would be much appreciated. Thanks.

 

Robert Burns

I think I'd start with some basic research. Depending on how old the church is, recent enough and the as built plans should be public record. I don' t know how long that kind of regulation has been law. Then of course the architect and builders should be known by the church itself or public record.

 

Okay, if records research and walking the yellow pages doesn't work you're going to find yourself in exploration and field test territory. Something like a bowling ball dropped from a modest height (INCHES!!) will generate a sound that will give you an idea what's under the marble. Gross tells would be frame sub floor sounds hollow and concrete sounds solid. another technique if there's spaces between the marble slabs you can drill a tiny hole and collect the cuttings. For instance, concrete cuttings will fizz under a drop of sulfuric acid.

 

Call a mason and ask how they'd find out. It's not like you're in competition and they may even know if and when it was laid, expanded, repaired, etc. you may have to drop in with a box of donuts and schmooze but what the hey, masonry outfits can probably use some hand forged items eh?

 

As a last resort you can try a geological investigation outfit, describe the situation, they may have or know who has a ground penetrating radar unit. THAT will do the job.

 

Well, okay THIS is the LAST last resort, drill exploratory anchor holes and use whatever's needed. I'd HATE to have to do that but it may be the only way.

 

Oh, and don't forget to let the folks at church know the problem, someone in the congregation may have just what you need and be happy to donate the use to the church. It'd be like applying the TPAAAP method to church steps.

 

I'd bloviate on but we have to go get hay. Later guys.

 

Frosty The Lucky.

Greetings Robert,

 

I have done a bunch of that type of installation .  If you post some pictures I might be able to help..  Lots of questions .. How many uprights.. Angle.. pad size..  One must be carful with that type of rail that might be subject to side thrust...  Marble is its own problem when set on concrete..  Many times I have done a test drill in an area of the church that does not show... Under a fixed pew or podium..  

 

Good luck

 

Jim

Hilti has the Best know anchors in the industry see here :

 

http://www.hilti.com/holcom/page/module/home/home_main.jsf?lang=en&nodeId=-8021

 

and are available all over the world a Rep from Hilti will work with you and help you find the correct anchor for the job you are doing . No I do not work for them , However I have used them many times even in the Prison systems where everything has to stay put or folks would get hurt .

 

Sam  

I have used Hilti fastenings in many high stress use situations,  and they are some of the best out there. Tho I really want to add a comment about Sam in the prison system, I will pass.

Best is to core drill holes and grout in posts. Way more sturdy and long lasting.

If you can't do any drilling, you might think of industrial glue.  I can't make any recommendations on what type, but, I know they have some unbelievably strong glues that might be the cats meow for your dilemma.  Of course, you would have to run some test pieces to confirm the glue's strength and to withstand the forces placed on it. Good luck    

There is Hilti/Upat etc. good industrial Product. And there is traditional lead, has only been used since Roman times so it may still work! Drill/core a hole a little larger than your post. about 2mm larger than a slip-fit if the post is round or 1mm to clear corner if square. be sure to vacum dust out of the hole before inserting post. if coring "do not use water" . Bend up a small piece of sheet metal to act as a funnel and pour in molten lead. Tamp the top down with a flat ended drift!

 

Try a test one in a bit of concrete at home first!  remember to "notch" below grade to prevent Pull-out.

 

In the event of a railing accidentally being set out of plumb. you can warm the base of the post with a torch and "adjust" wich is not do-able with hilti products.

 

In the event of you going the Hilti route be aware that they will try to sell you some peice of kit usually a "gun" of sorts that takes some special "two pack" this "gun" will be obsolete soon "thats in blacksmith terms" (we expect at least a lifetime from tools) it's just how Hilti does buisness. Next time(in a few years time) you will need to buy the next generation "gun" and no trade in on your perfectly good "obsolete " one...

 

Ian