Garage/future bar, floor is damp/wet in areas PLEASE HELP!

[theflame01]

i've been converting my oversized garage into a bar, i've battened out all my walls insulated them,boarded them and had them plastered. i've done the same with the ceiling. i've now had my concrete floor self leveled (used self leveling compound) about 5 weeks ago (IT WAS VERY DRY,POWDERY AND STONEY AT FIRST) and its still not totally dried out in places. When we first did it it seemed to dry fully for couple of days then the next day i went in and there was water on the surface in places. ever since its been damp in areas, i don't now if its because theres no heating in there yet ( i was told not to dry it with heaters) or if its because theres bad ventilation. i've recently been opening the double doors all day to dry it out this seems to work but again it comes back the next day.
Im stuck to now what to try next, i've thought about putting a dehumidifier in there to clear any excess moisture in the air would this help? Should i put heaters in there now? or could it be worst than that, could it be that the moistures coming from the ground!! I really hope not.
Please could any one help at all.
Thanks Dave

 

[mac391]

Theres more to converting a garage than meets the eye. The basic construction isn't the same as the rest of your house regarding ventilation, dpm etc.

Sounds like the moisture is comeing from the floor but even the lack of ventilation can cause damp to the floor.

Also sounds like you've paid attention to walls and insulation with no regard to the floor (i.e kingspan insulation, screed and DPM etc) And if your floor is damp, be sure to check that the batten/plasterboard to your walls does not meet the floor, there should be a gap of approx 50mm (covered by skirting)

There's too much to note realy.

Garage floors should still have a DPM under the concrete slab but during construction i've seen builders pierce the DPM after it has rained to allow water to ecape, then cover it with concrete, hence your DPM is useless !!

There may some some good quick fixes but the more info you can give the better .

 

[theflame01]

Thanks for reply.

The floor seemed realy dry before i put the floor leveling compound down so this is why im thinking its not coming from the ground but if it is, is there any way of stoping it with out haveing to dig it all up and start again (Very exspensive). Is there a paint or solution of some sort that would work. Or any thing at all?

What would you try first?

Thanks for your help.

 

[mac391]

Yes there are a few things you can do.

first check the moisture content of the floor, you'll probably have to get a floor specialist in to do it though as a hygrometer is needed to do it, expect to pay about £100 for the test.

If you havn't upgraded the sub-floor with dpm, insulation etc, you might always have problems though..

If the floor is reading as a high moisture content you can apply a liquid DPM that is painted on but quite expensive. F ball F75 or F76. www.f-ball.com You will then have to screed again.

Remember the floor might not be the problem but is worth eliminating so you know what to do next, i.e ventilation !! For a few weeks after pastering there will be a high moisture content escaping from the walls but this should stop once the walls are completely dry.

Unfortunately it's a process of elimination until you find the source of moisture, otherwise you might have wasted your time and money..