I am from Illinois. I want to build an oudoor deck for a friend in Maryland. The deck will be roughly 6' above grade. I say that at this height a 42" security rail along the perimiter of the deck is required by code. Others disagree, suggesting it needs to be only 36" high.

What can you tell me about the Maryland building code for deck rails?
Thanks, Yeow

I think you need check with your local building officials and see what they say. In my area here's how it goes deck height 0-29 inches no railing required 29 - 60 inches a railing of 36inches minimum is required. Above 60 inches they require a 42 inch railing and here anything higher than 6 feet they want an engineer to design it. You get the idea so check with whoever issues building permits in you're area they can help you. If I missed anything please let me know. GOOD LUCK, AC

You have answered well. My thoughts mirror your own.
Yeow

Yeow also ask about the ballister or picket spacing that they require here ballusters or pickets must be spaced so that a 4 inch sphere can not pass through that means 3.5 inches apart roughly. GOOD LUCK, AC

AC has been doing a great job on these posts. The 4" requirement is because the building code folks figure a small kids head is bigger than 4", they hate to see them get stuck.