check out something called the Chimney Balloon--it's inflatable
http://www.chimneyballoon.us/chimneyballoon.html

there are other inflatable ones as well--just google inflatable chimney damper

My last rental was in a house built in 1775. I had the exact same problem, and like you had hail, rain and snow in my fireplace.

My solution was to duct tape a piece of cardboard to fit the opening of the chimney right above the fireplace line, and to not use the fireplace.

It immediately stopped the heat loss as the "chimney effect" sorta sucked the cardboard into place and the duct tape secured it.

If there is no damper, the odds are pretty good that the chimney hasn't been cleaned out of kerosete (sp) buildup in ages- which is potentially hazardous as it is very flammable.

Get a piece of MDF (Medium Density Fiberboard) cut just a bit larger than the opening. Paint the board white to match the surrounding fireplace. You might use a framed print on top of that or cover the MDF with some upholstery fabric that uses accent colors compatible with your furnishings. You can get elaborate depending on your skills, budget and preferences.

I'd start by asking the landlord/property owner to fix this. Heating/cooling efficiency aren't to only reasons for a damper. You've already seen hail - what happens when there is a significant snow fall or tropical storm levels of rain? You also run the risk of getting birds or other critters in your living room. To me, a missing damper is equivalent to a missing window pane, and something the property owner should fix.

I agree with mpheels, but if that fails (or they are slow to act) then just fill a trash bag with newspaper and shove it up your chimney.

I also agree with mpheels. This is definitely something your landlord should fix.

Does a chimney without a damper even meet building code?

Apparently gas log fireplaces require that the damper is open all the time because of pilot light gasses. Is it operable?
You really should call the landlord to see if there is a solution that is safe and to code.
#Don't shove anything up the chimney that could collect moisture and harm the structure. That will cost you your deposit and possibly result in legal action against you. (Not that you would do that.) And may result in carbon monoxide build up in your house.

Styrofoam works great. My sister found a piece blocking the fireplace in her new house the first time she tried to use it. Lotsa smoke in the house. Before moving either undo or disclose the situation with your fireplace.

And mpheels is right, this is a job for the landlord. You are going to have precipitation collecting on top of whatever you block the chimney with and I'd be worrying about bats in my neighborhood! Capping a chimney can't be that hard.

AT- maybe a post or two about fireplaces and the proper care?

I just purchased a small, old cottage and had the chimney guy out to clean the before we lit a fire. Turns out that we don't have a damper. The old one had obviously corroded He told me that the damper would have to be "fit" into may fireplace (like a dental crown) and that it would cost about $750. Given that the small, old cottage has MANY more critical needs....the garbage bag of newspaper sounds like a good idea for now....

Does what the chimney guy said make sense?

Should I say chimney "sweep"?

Cut a piece of clear acrylic / polycarbonate plastic instead of MDF to fit neatly within the marble surround. Then it will be practically invisible. I did it myself. I think it cost less than $30. You can put a cute basket or something on hearth in front of the sheet to keep it in place.

Your landlord should absolutely take care of this, or pay your heating bills lol. I agree if you shove something up there water could collect and cause alot of damage (mortar, structural), and the gas line comment above is also valid.

Our upstairs bedroom had a similar situation and was part of a 3 stack chimney. Until we had a mason in to sort it all out I cut a piece of foam insulation, sized to exact opening, then attached that to a board (about 2 " larger on sides and top) which I painted black. Still got rain and critters but at least they didn't make it into the bedroom.

Again: I can't stress this enough - If you have a pilot light, DO NOT shove anything up in the chimney that will allow carbon monoxide to build up.
If you need to close it off, get a fitted front cover.

The first comment, re chimney balloons, is spot on. They are affordable, seal well, and by there very nature (filled with air) great insulators -- much better that the standard damper, which is just a sheet of metal.

However, I think you landlord should, at the very least, pay for it.

Mary17 -- yes, what the chimney sweep said makes sense. We have a damper that needs repair (the handle has become disconnected) and we can't even find someone willing to try to fix it. They are very customized installations, and repairs are challenging without re-doing the entire firebox and flue.

This is definitely not your problem to fix. Call the landlord and insist (s)he address this immediately.

I third the chimney balloon. We have them in our fireplaces (which have dampers, but are still drafty). The difference is AMAZING.

Yes on the chimney balloon, or, easier to cut than MDF is a piece of that hard foam insulation that you can cut to fit up above the firebox so it doesn't show, but the problem with either is that water will still land in there and then pool. Definitely alert the landlord and mention "MOISTURE PROBLEMS THAT MIGHT LEAD TO STRUCTURAL DAMAGE/MOLD." Maybe even put it in writing either hard copy snail mail and spring for the couple of dollars that means they sign to confirm receipt, or email. That might get his/her attention.

So I think that your landlord might not want to spend $750 to fix the chimney. Giving him other options could at least help you.

My name is Robin and I'm the original contributor. Thanks to everyone for their comments! We have been using the gas fireplace on occasion in the last month but always turn off the pilot light completely. I know you can leave it on all the time but we are just extra safe. We have yet to bring it up with the landlord but will be now. As some mentioned this may not be up to code - but that doesn't surprise me with other things we've dealt with here. A basic MDF board cut out to fit in the front by the granite sounds like something I can DIY. Thanks again!

Ditto to mpheels. If you had a hole in your roof, it would be your landlord's responsibility to fix it.

And guess what? You have a hole in your roof.

IDK if I'd worry about the pilot light offgassing: If the house is that old, it is far from airtight and should be fine. In our old house, we bought a fitted fireplace glass screen, which wasn't that expensive.

Re: MDF: I'd use plywood. MDF doesn't like moisture and it will be bound to catch some.

Stuffing something up the chimney will work. A chunk of foam rubber can be compressed and will then expand to fill the gap, but if there is ahy possibility of the fireplace being used, it is not a good idea.

If you do use the gas logs, be aware that, though they are great for atmosphere, they will end up sucking the warm air from your house right up the chimney with a net loss of heat.

Glass fireplace doors, available from big box home improvement stores.

Robin, sorry your introduction to Richmond had to be this. We're generally a nice and generous bunch of folks. Glad to have you here!

This seems like your landlord's problem if you ask me! Perhaps an oversight on their part.

We shoved a wad of fiberglass insulation in a damperless fireplace that we weren't using.It worked very well.

BTW, I would check with the building inspectors office just to find out what they say before talking to the landlord. Just go armed with information ahead of time.

Slightly off-topic, but yes, there are the occasional bats in Richmond. We helped some friends chase them out of their new house.

All the ideas of stuffing something up the chimney scare me a bit, especially since it was retrofitted for gas.

Two pieces of advice from all the comments that make the most sense to me:

A> Talk with landlord about fixing the issue.
B> A clear cover, either high-melting temp acrylic/plexi or a piece of plate glass.

For less than $200, you could ask the landlord to install one of these top sealing dampers.

http://www.homesaver.com/lyemance_fireplace_damper.aspx

I am thinking about getting one of these for my fireplace in order to save some cash also. However, I just have a regular masonry wood burning fireplace.

I'll have to say because the fireplace glass doors might not be the right way to go since generally older homes (older than 60 y/o) will probably need a custom sized glass door. This is the route that I had to go, in addition to potentially getting the new damper.