Restoration of mosaics in situ

Maria Mavrommati <maria [at] spark__net__gr> writes

>At the center of Thessaloniki Greece, found the palace complex of
>Galerious Maximus that was build about 300 AD. At this excavation
>some floor mosaics uncovered.
>...
>The reinstallation of mosaics is our next step. The problem we face
>is to fill those 3 meters with the proper and best stuff available.

The mosaic belongs to a period that the construction of the
substratum of the mosaics was developed.

The best solution would be to create a substratum similar to the
one the mosaic had before the excavation. This substratum held the
mosaic so many years.

If there was not any special construction underneath the mosaic I
believe it would be good if you made a substratum like this:

First of all you can use the earth you excavated to fill a big part
of the hole. It is very important to force the earth with heavy
tools so that it will be condensed before you continue. On the top
of this earth put big stones 30 - 40 cm high. This would keep the
water from coming up to the mosaic. Then use a thick stratum of
small stones and over this make a mortar with thick sand. After this
one made of thin sand. You can use cement but I wouldn't recommend
it because of the sulfuric ions. You can also make a metallic net,
but don't use iron. Instead of iron you can use titanium.

On this you can place the mosaic. It is very important to create a
step of mortar around the edges of the mosaic because this way the
mosaic will not fall apart.

Thanasis Velios
Conservation studies, Athens

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                  Conservation DistList Instance 9:41
                Distributed: Saturday, November 11, 1995
                        Message Id: cdl-9-41-003
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