is it to early to put 9 day olds out in 10x12 gambrel shed coop

[lalaland]

not sure a 100 watt bulb will give sufficient heat. You could dtry it without the chicks, but then you would need a thermometer (2 bucks at the hardware store) to see if you can maintain the right temp with just the bulb. Once you have that down, add the chicks.

Would be easier if you just invested in a brooder lamp - looks like the kind of temp light found in hardware stores, too - be sure you get one with a ceramic, not plastic, socket - the part that sticks up out of the aluminum shade should be ceramic. Use a heat lamp bulb - you will use this in the winter sometimes with your chickens, and when you have an ill chicken and want to provide extra warmth, etc.

IMHO

 

[Judy]

Agree with lalaland and with sectioning off a part of the coop. Around here the brooder lamp and red heat bulb are about $15. Many find that 100W bulbs, because they are white light, disturb the chickens, cause them to sleep less and peck more. A cheap thermometer would at least give you an idea before you move the chicks. If it's not exactly 90 or whatever, try it anyway. The chicks will tell you whether they are warm enough. Mine never liked temps as high as are recommended.