Leaking base seal

[Physopto]

If for some chance the CT1 does not solve your problem, rather than building an internal brick wall, you could try UPVA window sill on edge, The thinner variety bends easily. You can try bonding it to the floor with CT1. It will save you some considerable floor space and the likelihood of a nasty  trip. The sill I am thinking of  is the foam filled variety.  You will only need a small dam  a few inches high, so the smallest sill will do it. It can be bonded virtually touching the dome wall.

Derek

[rubecula]

I've found a temporary solution for my observatory paddling pool.     The plastic sheeting appears to be keeping the place dry while I try to work out a permenant solution.  As you can see from the picture the sealant was having no affect at all, it hadn't stuck to either the concrete or fibreglass and pulled out of the joint with little effort.  My plan is to wait until we get some good spells of dry weather, probably in the summer when the nights are very short.  At which point, the current plan is to dismantle the observatory, give the concrete two coats of epoxy resin and then replace the observatory laying it on a very thick bead of CT1.

In the meantime I'm now the proud owner of an ELA dessicant dehumidifier which is drying things out at a rapid rate, so hopefully I will be able to get the flooring back down tomorrow and be ready for the next clear spell (although there;s not much sign of that in the weather forecast).

I must thank Skipper Billy for the help he has given me in all this, he's been a star!!

[CSM]

I have a Pulsar and exactly the same problem with water seeping in underneath, and also through the bottom hole where the door catch latches down.  This is not helped by the fact that the door faces directly into the prevailing winds - and here it is very wet with an average of about 72" rain a year (I have a weather station).  Last summer I did put 3 layers of aquaprufe down and then a pond layer and then the rather flimpsy damp proof sheet that Pulsar supply, then the rubber flooring.  Still seeps up through the floor when really wet and when I lift the rubber flooring it is underneath.  I usually end up mopping it up when we have dry weather (a distant memory at the moment) and dry the rubber flooring in the nearby greenhouse.  Maybe in the summer I will lift the observatory and rotate it, or maybe just try to create a slight runoff around it and sealing with one of the products mentioned here.  At one stage I did cover the scope but discovered that that merely created condensation.  Now I rely on the natural ventilation and have also sprayed quite a lot of items with ACF-50.