Making a ground bed for my Cub Scout

[Armymutt]

My son's first ever camping trip is on Halloween.  We are in NC, for weather reference.  We'll be staying in my 33 year old LL Bean tent.  I haven't been camping outside of the Army since 1994.  Still have my Thermarest 3/4 length self-inflating pad from my Philmont trip.  I was thinking of putting him in a square sleeping bag on top of the Thermarest.  Since I'm old and beat up from being an Infantryman and a Paratrooper, I'm trying to decide between a twin-size air mattress or picking up a Big Agnes sleeping bag and pad combo.  Kind of depends on availability right now.  I'm planning on taking these on motorcycle trips, so it's already a planned purchase.  Will I have to turn in my Camping Merit Badge if I decide to take the big mattress?   The 18 year old in me says "weenie"!  

[Rock Doc]

Wee man should be fine as you suggest. As for you, I'd go with an insulated air pad (Big Agnes, REI, etc.). They're close to 3-inches thick and allow plenty of isolation from the odd root or rock. Air mattresses are bulky and cold, you'd need to use the thermarest on top of the mattress to prevent a chilly night. Good luck!

[qwazse]

I loved (and still miss dearly) my Big Angus!

Try sleeping on the floor one evening. If you only loose a couple of hours, you’ll be fine with a thermarest.

Your scout is probably so light he won’t notice a thing.

[Sentinel947]

Two recommendations:  test out the pad to make sure it holds air still. Also, I'd recommend setting up your tent and hitting it with the hose. If it's 33 years old, it may not be quite as waterproof as you'd like it to be.... 

As for sleeping pad,  the Big Angus pads are delightful. I personally use a Thermarest Xlite for backpacking, but it's a little small and is trading comfort for weight savings. I'm small in stature, so I can use it for normal trips too. True Air mattresses are always nice, but are limited to car camping. 

If you are mostly doing car camping, or want to bring a "non-camper"(Spouse?) sometime, going with one of those larger than twin size inflatable air mattresses might be the right play. Also good if you have a larger family and want to only rent one hotel room with two beds. Inflate that big air mattress on the floor and stick two more kids there. Also good for sleepovers if your kids have friends over. If you do that for your trip, you and your son could just share the inflatable air mattress.

Have a good trip!